24Ao - Hi-Fi System MOTU - Free user manual and instructions

Product Type	Hi-Fi System (Audio Interface)
Channels	24 analog outputs, 24 ADAT optical inputs/outputs
Analog Outputs	24 balanced on 3x DB-25 or 6x Phoenix connectors
Digital I/O	24-channel ADAT optical (44.1/48 kHz) or 12-channel (88.2/96 kHz)
Sample Rates	44.1, 48, 88.2, 96, 176.4, 192 kHz
Dynamic Range (Analog Out)	123 dB A-weighted
THD+N	-110 dB (0.0003%) @ -1 dBFS, 1 kHz
Frequency Response	+0, -0.1 dB, 20 Hz - 20 kHz
Max Output Level	+20 dBu
Output Trim Range	24 dB (-4 to +20 dBu in 1 dB steps)
Computer Connectivity	USB 2.0 (compatible with USB 3.0) or AVB Ethernet (Mac with Thunderbolt)
AVB Networking	IEEE 802.1, up to 5 devices via MOTU AVB Switch
Onboard DSP Mixer	48 inputs, 12 busses, 32-bit floating point, effects (EQ, compressor, reverb)
Control	Web app (MOTU AVB Control) via browser, iPad/iPhone app
Front Panel Metering	Analog output and ADAT optical meters, LCD display
Word Clock	BNC In/Out/Thru, 75 ohm termination
Power Supply	Internal universal: 100-240 VAC, 50/60 Hz, 0.5A max
Power Consumption	35 watts
Form Factor	19-inch rack mount (1U, brackets removable for desktop)
Operating Temperature	10°C to 40°C (50°F to 104°F)

Frequently Asked Questions - 24Ao MOTU

How do I connect the 24Ao to my computer?

Use a standard USB cable to connect the USB 2.0 port on the rear panel to your computer. For AVB Ethernet operation, connect the NETWORK port to a Mac with Thunderbolt running OS X 10.10 or later using a CAT-5e or CAT-6 cable.

What is the maximum number of channels I can use simultaneously?

At 44.1 or 48 kHz, you can use 24 analog outputs and 24 ADAT optical inputs plus 24 outputs, totaling 72 channels. With AVB networking, an additional 96 channels are possible.

How do I access the mixer and settings?

Launch the MOTU AVB Control web app by using the MOTU AVB Discovery app (Mac), the MOTU AVB WebUI Setup (Windows), or by typing the device's IP address into a web browser. The web app runs on any device connected to the same network.

Can I use the 24Ao without a computer?

Yes, you can operate it as a stand-alone mixer. Connect a Wi-Fi router to the NETWORK port and control mixing via the web app on a tablet or smartphone.

How do I update the firmware?

Connect the 24Ao to the internet via a network cable. In the Device tab of the web app, click 'More Info' on the update banner to install. For offline updates, download the firmware file and use 'Update from File'.

What cable do I need for analog outputs?

Use a standard Panasonic/Tascam format DB-25 cable (AES-59) with 4-40 retaining screws, or Phoenix screw-block connectors for 4-channel connections. Do not use both on the same bank simultaneously.

Why am I hearing clicks and pops?

Clicks and pops are often due to incorrect word clock synchronization. Ensure all digital devices are locked to the same clock source. Check the Clock Status in the Device tab. Also, verify hard drive performance and reduce buffer sizes if needed.

How do I reduce monitoring latency?

In the MOTU AVB USB Control Panel (Windows), lower the ASIO Buffer Size. On Mac, reduce the buffer size in your host audio software. For zero-latency monitoring, use the on-board mixer's direct hardware playthrough.

Can I connect multiple 24Ao units together?

Yes, connect up to five MOTU AVB interfaces via a MOTU AVB Switch using standard Ethernet cables. Each interface appears in the web app for unified control. For more than five, use multiple switches.

How do I reset the device to factory defaults?

On the front panel, press SEL to enter the menu, navigate to Settings > Factory Default, and press SEL twice. Alternatively, in the Device tab of the web app, click 'Restore Factory Presets'.

USER MANUAL 24Ao MOTU

1280 Massachusetts Avenue

Cambridge, MA 02138

Business voice: [phone]

Business fax: [phone]

Web site: www.motu.com

Tech support: www.motu.com/support

SAFETY PRECAUTIONS AND ELECTRICAL REQUIREMENTS FOR THE 24Ai AND 24Ao ("PRODUCT")

CAUTION! READ THIS SAFETY GUIDE BEFORE YOU BEGIN INSTALLATION OR OPERATION. FAILURE TO COMPLY WITH SAFETY INSTRUCTIONS COULD RESULT IN BODILY INJURY OR EQUIPMENT DAMAGE.

HAZARDOUS VOLAGES: CONTACT MAY CAUSE ELECTRIC SHOCK OR BURN. TURN OFF UNIT BEFORE SERVICING.

WARNING: TO REDUCE THE RISK OF FIRE OR ELECTRICAL SHOCK, DO NOT EXPOSE THIS APPLIANCE TO RAIN OR OTHER MOISTURE.

CAUTION: TO REDUCE THE RISK OF ELECTRICAL SHOCK, DO NOT REMOVE COVER. NO USER-SERVICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED SERVICE PERSONNEL.

WARNING: DO NOT PERMIT FINGERS TO TOUCH THE TERMINALS OF PLUGS WHEN INSTALLING OR REMOVING THE PLUG TO OR FROM THE OUTLET.

WARNING: IF NOT PROPERLY GROUNDED THE MOTU PRODUCT COULD CAUSE AN ELECTRICAL SHOCK.

The MOTU product is equipped with a three-conductor cord and grounding type plug which has a grounding prong, approved by Underwriters' Laboratories and the Canadian Standards Association. This plug requires a mating three-conductor grounded type outlet as shown in Figure A below. If the outlet you are planning to use for the MOTU product is of the two prong type, DO NOT REMOVE OR ALTER THE GROUNDING PRONG IN ANY MANNER. Use an adapter as shown below and always connect the grounding lug to a known ground. It is recommended that you have a qualified electrician replace the TWO prong outlet with a properly grounded THREE prong outlet. An adapter as illustrated below in Figure B is available for connecting plugs to two-prong receptacles.

Figure A Figure B

3-prong plug Grounding prong Properly grounded 3-prong outlet

Grounding lug Screw 3-prong plug Adapter Make sure this is connected to a known ground. Two-prong receptacle

WARNING: THE GREEN GROUNDING LUG EXTENDING FROM THE ADAPTER MUST BE CONNECTED TO A PERMANENT GROUND SUCH AS TO A PROPERLY GROUNDED OUTLET BOX. NOT ALL OUTLET BOXES ARE PROPERLY GROUNDED.

If you are not sure that your outlet box is properly grounded, have it checked by a qualified electrician. NOTE: The adapter illustrated is for use only if you already have a properly grounded two-prong receptacle. Adapter is not allowed in Canada by the Canadian Electrical Code. Use only three wire extension cords which have three-prong grounding type plugs and three-prong receptacles which will accept the MOTU product plug.

IMPORTANT SAFEGUARDS

1. Read these instructions. All the safety and operating instructions should be read before operating the product.
2. Keep these instructions. These safety instructions and the product owner's manual should be retained for future reference.
3. Heed all warnings. All warnings on the product and in the owner's manual should be adhered to.
4. Follow all Instructions. All operating and use instructions should be followed.
5. Do not use the product near water.
6. Cleaning - Unplug the product from the computer and clean only with a dry cloth. Do not use liquid or aerosol cleaners.
7. Ventilation - Do not block any ventilation openings. Install in accordance with the manufacturer's instructions.
8. Overloading - Do not overload wall outlets and extension cords as this can result in a risk of fire or electrical shock.
9. Power switch - Install the product so that the power switch can be accessed and operated at all times.
10. Disconnect - The main plug is considered to be the disconnect device for the product and shall remain readily operable.
11. Accessories - Only use attachments/accessories specified by the manufacturer.
12. Surge protection - Unplug the product during lightning storms or when unused for long periods of time.

13. Power amplifiers- Never attach audio power amplifier outputs directly to any of the unit's connectors.

14. Heat - Do not install the product near any heat sources such as radiators, heat registers, stoves, or another apparatus (including an amplifier) that produces heat.

15. Grounding - Do not defeat the safety purpose of the polarized or grounding-type plug. A polarized plug has two blades with one wider than the other. A grounding-type plug has two blades and a third grounding prong. The wide blade or the third prong are provided for your safety. If the provided plug does not fit into your outlet, consult and electrician for replacement of the obsolete outlet.

16. Power cord - Protect the product power cord from being walked on or pinched by items placed upon or against them. Pay particular attention to cords and plugs, convenience receptacles, and the point where they exit from the unit.

17. Placement - Use only with the cart, stand, tripod, bracket or table specified by the manufacturer, or sold with the product. When a cart is used, use caution when moving the cart/apparatus combination to avoid injury from tip-over.

18. Servicing - Refer all servicing to qualified service personnel. Servicing is required when the product has been damaged in any way, such as when a power-supply cord or plug is damaged, liquid has been spilled or objects have fallen into the product, the product has been exposed to rain or moisture, does not operate normally, or has been dropped.

19. Power Sources - Refer to the manufacturer's operating instructions for power requirements. Be advised that different operating voltages may require the use of a different line cord and/or attachment plug.

20. Installation - Do not install the product in an unventilated rack, or directly above heat-producing equipment such as power amplifiers. Observe the maximum ambient operating temperature listed below.

21. Replacement Parts - When replacement parts are required, be sure the service technician has used replacement parts specified by the manufacturer or have the same characteristics as the original part. Unauthorized substitutions may result in fire, electric shock or other hazards.

22. Safety Check - Upon completion of any service or repairs to this MOTU product, ask the service technician to perform safety checks to determine that the product is in safe operating conditions.

ENVIRONMENT, HEAT AND VENTILATION

Operating Temperature: 10°C to 40°C (50°F to 104°). The product should be situated away from heat sources or other equipment that produces heat. When installing the product in a rack or any other location, be sure there is adequate space around the product to ensure proper ventilation. Improper ventilation will cause overheating and can damage the unit.

TO REDUCE THE RISK OF ELECTRICAL SHOCK OR FIRE

Do not handle the power cord with wet hands. Do not pull on the power cord when disconnecting it from an AC wall outlet. Grasp it by the plug. Do not expose this apparatus to rain or moisture. Do not place objects containing liquids on it.

AC INPUT

100 - 240VAC \~ • 50 / 60Hz • 0.5A max

Contents

Part 1: Getting Started

7 Quick Start Guide
9 24Ai Front Panel
10 24Ai Rear Panel
11 24Ao Front Panel
12 24Ao Rear Panel
13 MOTU AVB Control Web App
23 About Your MOTU AVB Audio Interface
27 Packing List and System Requirements
29 Software Installation
33 Hardware Installation

Part 2: Using your MOTU interface

47 Presets
53 The Front Panel LCD
55 Working with Host Audio Software
63 Mixer Effects
69 Networking

Part 3: Appendices

77 Troubleshooting
79 Audio Specifications
81 Mixer Schematics
85 D-sub Connector Specifications
87 Updating Firmware
89 OSC Support
91 Index

About the Mark of the Unicorn License Agreement and Limited Warranty on Software

TO PERSONS WHO PURCHASE OR USE THIS PRODUCT: carefully read all the terms and conditions of the "click-wrap" license agreement presented to you when you install the software. Using the software or this documentation indicates your acceptance of the terms and conditions of that license agreement.

Mark of the Unicorn, Inc. ("MOTU") owns both this program and its documentation. Both the program and the documentation are protected under applicable copyright, trademark, and trade-secret laws. Your right to use the program and the documentation are limited to the terms and conditions described in the license agreement.

Reminder of the terms of your license

This summary is not your license agreement, just a reminder of its terms. The actual license can be read and printed by running the installation program for the software. That license agreement is a contract, and clicking "Accept" binds you and MOTU to all its terms and conditions. In the event anything contained in this summary is incomplete or in conflict with the actual click-wrap license agreement, the terms of the click-wrap agreement prevail.

YOU MAY: (a) use the enclosed program on a single computer; (b) physically transfer the program from one computer to another provided that the program is used on only one computer at a time and that you remove any copies of the program from the computer from which the program is being transferred; (c) make copies of the program solely for backup purposes. You must reproduce and include the copyright notice on a label on any backup copy.

YOU MAY NOT: (a) distribute copies of the program or the documentation to others; (b) rent, lease or grant sublicenses or other rights to the program; (c) provide use of the program in a computer service business, network, time-sharing, multiple CPU or multiple user arrangement without the prior written consent of MOTU; (d) translate, adapt, reverse engineer, decompile, disassemble, or otherwise alter the program or related documentation without the prior written consent of MOTU.

MOTU warrants to the original licensee that the disk(s) on which the program is recorded be free from defects in materials and workmanship under normal use for a period of ninety (90) days from the date of purchase as evidenced by a copy of your receipt. If failure of the disk has resulted from accident, abuse or misapplication of the product, then MOTU shall have no responsibility to replace the disk(s) under this Limited Warranty.

THIS LIMITED WARRANTY AND RIGHT OF REPLACEMENT IS IN LIEU OF, AND YOU HEREBY WAIVE, ANY AND ALL OTHER WARRANTIES, BOTH EXPRESS AND IMPLIED, INCLUDING BUT NOT LIMITED TO WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE LIABILITY OF MOTU PURSUANT TO THIS LIMITED WARRANTY SHALL BE LIMITED TO THE REPLACEMENT OF THE DEFECTIVE DISK(S), AND IN NO EVENT SHALL MOTU OR ITS SUPPLIERS, LICENSORS, OR AFFILIATES BE LIABLE FOR INCIDENTAL OR CONSEQUENTIAL DAMAGES, INCLUDING BUT NOT LIMITED TO LOSS OF USE, LOSS OF PROFITS, LOSS OF DATA OR DATA BEING RENDERED INACCURATE, OR LOSSES SUSTAINED BY THIRD PARTIES EVEN IF MOTU HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. THIS WARRANTY GIVES YOU SPECIFIC LEGAL RIGHTS WHICH MAY VARY FROM STATE TO STATE. SOME STATES DO NOT ALLOW THE LIMITATION OR EXCLUSION OF LIABILITY FOR CONSEQUENTIAL DAMAGES, SO THE ABOVE LIMITATION MAY NOT APPLY TO YOU.

Update Policy

In order to be eligible to obtain updates of the program, you must complete and return the attached Mark of the Unicom Purchaser Registration Card to MOTU.

Copyright Notice

Copyright © 2015, 2014 by Mark of the Unicorn, Inc. All rights reserved. No part of this publication may be reproduced, transmitted, transcribed, stored in a retrieval system, or translated into any human or computer language, in any form or by any means whatsoever, without express written permission of Mark of the Unicorn, Inc., 1280 Massachusetts Avenue, Cambridge, MA, 02138, U.S.A.

Limited Warranty on Hardware

Mark of the Unicorn, Inc. and S&S Research ("MOTU/S&S") warrant this equipment against defects in materials and workmanship for a period of TWO (2) YEARS from the date of original retail purchase. This warranty applies only to hardware products; MOTU software is licensed and warranted pursuant to separate written statements.

If you discover a defect, first write or call Mark of the Unicorn at [phone] to obtain a Return Merchandise Authorization Number. No service will be performed on any product returned without prior authorization. MOTU will, at its option, repair or replace the product at no charge to you, provided you return it during the warranty period, with transportation charges prepaid, to Mark of the Unicorn, Inc., 1280 Massachusetts Avenue, MA 02138. You must use the product's original packing material for in shipment, and insure the shipment for the value of the product. Please include your name, address, telephone number, a description of the problem, and the original, dated bill of sale with the returned unit and print the Return Merchandise Authorization Number on the outside of the box below the shipping address.

This warranty does not apply if the equipment has been damaged by accident, abuse, misuse, or misapplication; has been modified without the written permission of MOTU, or if the product serial number has been removed or defaced.

ALL IMPLIED WARRANTIES, INCLUDING IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ARE LIMITED IN DURATION TO TWO (2) YEARS FROM THE DATE OF THE ORIGINAL RETAIL PURCHASE OF THIS PRODUCT.

THE WARRANTY AND REMEDIES SET FORTH ABOVE ARE EXCLUSIVE AND IN LIEU OF ALL OTHERS, ORAL OR WRITTEN, EXPRESS OR IMPLIED. No MOTU/S&S dealer, agent, or employee is authorized to make any modification, extension, or addition to this warranty.

MOTU/S&S ARE NOT RESPONSIBLE FOR SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES RESULTING FROM ANY BREACH OF WARRANTY, OR UNDER ANY LEGAL THEORY, INCLUDING LOST PROFITS, DOWNTIME, GOODWILL, DAMAGE OR REPLACEMENT OF EQUIPMENT AND PROPERTY AND COST OF RECOVERING REPROGRAMMING, OR REPRODUCING ANY PROGRAM OR DATA STORED IN OR USED WITH MOTU/S&S PRODUCTS.

Some states do not allow the exclusion or limitation of implied warranties or liability for incidental or consequential damages, so the above limitation or exclusion may not apply to you. This warranty gives you specific legal rights, and you may have other rights which vary from state to state.

MOTU, Digital Performer, AudioDesk, Mark of the Unicorn and the unicorn silhouette logo are trademarks of Mark of the Unicorn, Inc.

Thunderbolt and the Thunderbolt logo are trademarks of Intel Corporation in the U.S. and/or other countries.

This equipment has been type tested and found to comply with the limits for a class B digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instruction manual, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause interference to radio or television equipment reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by any combination of the following measures:

• Relocate or reorient the receiving antenna

- Increase the separation between the equipment and the receiver

• Plug the equipment into an outlet on a circuit different from that to which the receiver is connected

If necessary, you can consult a dealer or experienced radio-television technician for additional assistance.

PLEASE NOTE: only equipment certified to comply with Class B (computer input/output devices, terminals, printers, etc.) should be attached to this equipment, and it must have shielded interface cables in order to comply with the Class B FCC limits on RF emissions.

WARNING: changes or modifications to this unit not expressly approved by the party responsible for compliance could void the user's authority to operate the equipment.

Part 1

Getting Started

Quick Start Guide

Thank you for purchasing a MOTU AVB interface! Follow these easy steps to get started quickly.

1 Download and run the MOTU AVB Installeror MOTU AVB USB Installer.exefound here:

http://www.motu.com/avb

2 (Optional) For access to your MOTU interface from your iPad or iPhone, download the MOTU AVB Discovery app from the Apple App Store.

Your iPhone and iPad must be on the same WiFi network as your computer.

3 Connect your MOTU interface to your computer with a USB cable (included). If you have a Thunderbolt-equipped Mac running OS X Yosemite (10.10) or later, you can alternately connect your MOTU interface to the Mac's Ethernet port with a standard CAT-5e or CAT-6 Ethernet cable (sold separately).

4 Switch on your MOTU interface.

5 Open the MOTUAVB Controlweb app by doing one of the following:

■ If you have a Mac, choose your MOTU interface from the MOTU AVB Discovery app menu.

MOTU AVB Discovery app menu MOTU AVB Devices 24Ai

■ If you have a PC, launch the MOTU AVB WebUI Setup shortcut found on the Windows desktop or in Start menu> All Programs> MOTU

■ From your iPad or iPhone, launch the MOTU AVB Discovery app, and tap your interface.

- You should now see theMOTUAVB Controlweb app in your browser, as shown on page 14. If not, visit Appendix A, "Troubleshooting" (page 77).

■ For advanced network options, and device discovery from any modern browser, see chapter 9, "Networking" (page 69).

6 Choose a preset from the Quick Setup.

Quick Setup How are you planning to use your 24Ao? Audio Interface For operation as a standard audio interface. Hardware inputs and outputs are accessible from your computer, and the mixer and audio networking features are disabled. Cancel OK

Preset Application

Audio interface Operate as a standard audio interface.
Stand-alone mixer Operate as a stand-alone mixer, where all inputs are mixed to the main outs and monitor outs.
Interface + mixer A combination of the above two presets.
Live recording with monitor mixing	Record a live concert or recording session, with a full monitor mix.
Stage I/O Route audio inputs from one AVB interface to another, through Ethernet cabling.
Studio Input Expander	Routes the expansion unit's physical inputs to the main system using AVB network streams.
Studio Output Expander	Routes the main systems's AVB network streams to physical outputs on the expansion unit.
Optical Converter Multi-channel analog-to-digital or digital-to-analog converter.

24Ai Front Panel

24Ai AVD TRI-PEREO USD ANALOG INPUTS ID BACK SSL ANALOG IN OPTICAL MOTU 96k Int CLOCK 32

1. ANALOG INPUT METERS for the twenty-four analog inputs.

2. ADAT OPTICAL input and output metering. At 1x sample rates (44.1 or 48 kHz), there are twenty-four channels of input and output. At 2x (88.2 or 96 kHz), there are twelve channels.

3. The CLOCK section displays the current operating sample rate and clock mode (source) for the unit.

4. POWER SWITCH: AVB and USB are "plug-and-play" protocols. That means you can turn the 24Ai off and back on without restarting your computer.

5. Push SEL (select) to enter the LCD menu. Push the ARROW buttons to scroll through menu options. Push again to descend into the submenus, if applicable. To choose the current setting, push SELECT a third time. Push BACK to return to the previous menu level, and do so repeatedly to exit the menu altogether.

6. Push ID to display network settings for the device, including its IP address.

24Ai Rear Panel

WORD CLOCK 100-240 VAD ~ 50/60 Hz + 0.5A max OUT/THRU IN—OUT IN—OUT INTERNATIONAL NETWORK USB2 192 kHz BALANCED UNBALANCED ANALOG IN 9-16 1-8 1-7 1-6 1-5 1-4 1-3 1-2 1-1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80

1. The 24Ai is equipped with an auto-switching international power supply.
2. BNC word clock jacks. Use them for a variety of applications, such as digital transfers with devices that cannot slave to the clock supplied by their digital I/O connection with the 24Ai.

3. These three ADAT optical "lightpipe" jacks provide 24 channels of 24-bit ADAT optical digital I/O at 1x sample rates (44.1 or 48 kHz) and 12 channels at 2x sample rates (88.2 or 96 kHz). They are disabled at higher sample rates. The IN and OUT ports on the right provide channels 1-8 (or 1-4), the left-hand ports provide channels 9-16 (or 5-8), and the third bank below provides channels 17-24 (or 9-12).

4. These three 8-channel banks provide 24 channels of balanced analog input. You can use either a standard 8-channel Panasonic/Tascam format DB-25 cable or the two 4-channel Phoenix connectors. DO NOT connect both the D-sub and Phoenix connectors for a bank at the same time. You can, however, use different connectors across banks, if needed (for example, D-sub for channels 1-8 and Phoenix for channels 9-16). The pin-outs for the Phoenix connectors are indicated on the label of the connector; for the D-sub pinouts, see Appendix D, "D-sub Connector Specifications" page (85).

5. Connect the 24Ai to the computer with this USB 2.0 port using a standard USB cable. You can connect it to a USB 2.0 or 3.0 port on the computer.

6. This AVB ethernet port provides industry standard IEEE 802.1 network connectivity to other network devices. Examples include:

■ Another 24Ai or any other MOTU AVB-equipped audio interface, such as the 1248, 8M, 16A, 24Ai, 24Ao, 112D, Monitor 8, etc.
■ A standard ethernet hub or Wi-Fi router (for internet connection and communication with the MOTU AVB Control web app software).
■ A standard AVB Ethernet switch for high-speed, low-latency, high-capacity audio connectivity to an AVB audio network.
A recent-generation Mac (any Mac with a Thunderbolt port) running OS X Yosemite (10.10) or later. This allows you to operate the 24Ai as an audio interface over Ethernet.

1. Use a standard (AES-59) Panasonic/Tascam DB-25 cable.
2. Make sure the retaining screws have standard 4-40 threading (not metric threading).
3. These are the pin-outs for the D-sub connector.

24Ao Front Panel

24Ao 24 CHANNEL BALANCED ANALOG OUTPUTS USB OUT AVB RICHMON USB ID BACK SEL ANALOG OUT OPTICAL 96k INT MOTU 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 OUT CLOCK OFFICE 32

1. ANALOG OUTPUT METERS for the twenty-four analog outputs.

2. ADAT OPTICAL input and output metering. At 1x sample rates (44.1 or 48 kHz), there are twenty-four channels of input and output. At 2x (88.2 or 96 kHz), there are twelve channels.

3. The CLOCK section displays the current operating sample rate and clock mode (source) for the unit.

4. POWER SWITCH: AVB and USB are "plug-and-play" protocols. That means you can turn the 24Ao off and back on without restarting your computer.

5. Push SEL (select) to enter the LCD menu. Push the ARROW buttons to scroll through menu options. Push again to descend into the submenus, if applicable. To choose the current setting, push SELECT a third time. Push BACK to return to the previous menu level, and do so repeatedly to exit the menu altogether.

6. Push ID to display network settings for the device, including its IP address.

24Ao Rear Panel

1 24Hz 100-240 VAC 60/60 Hz • 0.5A max OUT/THRU WORD CLOCK —9:3E —DPT —1.8 IN — OUT IN — OUT OUT/THRU —17-24/8-12— NETWORK USB2 17-24 102 kHz BALANCED/UNBALANCED ANALOG OUT 9-16 10 13 14 13 12 11 10 9 1 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 ① ② ③ ④ ⑤ ⑥ ⑦ ⑧ ⑨

1. The 24No is equipped with an auto-switching international power supply.
2. BNC word clock jacks. Use them for a variety of applications, such as digital transfers with devices that cannot slave to the clock supplied by their digital I/O connection with the 24Ao.

3. These three ADAT optical "lightpipe" jacks provide 24 channels of 24-bit ADAT optical digital I/O at 1x sample rates (44.1 or 48 kHz) and 12 channels at 2x sample rates (88.2 or 96 kHz). They are disabled at higher sample rates. The IN and OUT ports on the right provide channels 1-8 (or 1-4), the left-hand ports provide channels 9-16 (or 5-8), and the third bank below provides channels 17-24 (or 9-12).

4. These three 8-channel banks provide 24 channels of balanced analog output. You can use either a standard 8-channel Panasonic/Tascam format DB-25 cable or the two 4-channel Phoenix connectors. DO NOT connect both the D-sub and Phoenix connectors for a bank at the same time. You can, however, use different connectors across banks, if needed (for example, D-sub for channels 1-8 and Phoenix for channels 9-16). The pin-outs for the Phoenix connectors are indicated on the label of the connector; for the D-sub pinouts, see Appendix D, "D-sub Connector Specifications" page (85).

5. Connect the 24Ao to the computer with this USB 2.0 port using a standard USB cable. You can connect it to a USB 2.0 or 3.0 port on the computer.

6. This AVB ethernet port provides industry standard IEEE 802.1 network connectivity to other network devices. Examples include:

■ Another 24Ao or any other MOTU AVB-equipped audio interface, such as the 1248, 8M, 16A, 24Ai, 24Ao, 112D, Monitor 8, etc.
■ A standard ethernet hub or Wi-Fi router (for internet connection and communication with the MOTU AVB Control web app software).
■ A standard AVB Ethernet switch for high-speed, low-latency, high-capacity audio connectivity to an AVB audio network.
A recent-generation Mac (any Mac with a Thunderbolt port) running OS X Yosemite (10.10) or later. This allows you to operate the 24Ao as an audio interface over Ethernet.

1. Use a standard (AES-59) Panasonic/Tascam DB-25 cable.
2. Make sure the retaining screws have standard 4-40 threading (not metric threading).
3. These are the pin-outs for the D-sub connector.

MOTU AVB Control Web App

OVERVIEW

MOTU AVB Controls a web app that gives you complete control over your MOTU audio interface. If you have several MOTU AVB interfaces networked together, such as the 24Ai, 24Ao and 8M, you can control them all. If you are working with a large-scale network of many MOTU AVB interfaces, you can access and control any device on the network.

IT'S NOT ON YOUR HARD DRIVE

The MOTU AVB Control web app is served from the 24Ai and 24Ao hardware itself, therefore it is not an application on your computer's hard drive. Instead, access it by using the MOTU AVB Discoveryapp for Mac, the MOTU AVB WebUI Setup for Windows or through your browser by typing your MOTU device's IP Address.

USE YOUR FAVORITE WEB BROWSER

The MOTU AVB Control web app runs in any modern web browser on any device connected to your MOTU interface, either directly or wirelessly through a WiFi network. You can use any device you wish: a desktop computer, laptop, iPad, tablet, iPhone or smart phone. If it can run a web browser, it can run the web app. You can use any browser you prefer: Chrome, Firefox, Safari, IE 11 etc. The latest versions are strongly recommended.

CONTROL FROM MULTIPLE DEVICES

You can run the web app on multiple host devices simultaneously.

RUN THE INSTALLER, GET THE APP

Visit www.motu.com/avb to get the latest MOTU AVB installer and run it on your computer to install the MOTU AVB Discoveryapp (Mac) or MOTU AVB WebUI Setup(Windows) and other software elements. Visit the Apple App Store to download the discovery app onto your iPad or iPhone.

MAKE HARDWARE AND NETWORK CONNECTIONS

Connect your MOTU interface to your computer or laptop with a USB cable. Make sure your iPad, iPhone, tablet or smartphone is connected to the same WiFi network as your computer or device. You can use any network scenario explained in "Setup for web app control" on page 38.

LAUNCHING THE WEB APP

To launch the web app, do any of the following:

- If you have a Mac, choose the 24Ai or 24Ao from the MOTU AVB Discovery app menu, as shown below. If you are on Windows, launch the MOTU AVB WebUI Setup shortcut on the Windows desktop or in Start menu> All Programs> MOTU

MOTU AVB Devices 24Ai 24Ao

■ From your iPad or iPhone, launch the MOTU AVB Discovery app.
■ In your favorite web browser, type this URL: localhost:1280. (This URL requires a USB connection to the 24Ai or 24Ao.)
- If the 24Ai or 24Ao Ethernet port is connected to your Ethernet or Wi-Fi network, type the unit's IP address (see below) into your browser.

You should now see the MOTU AVB Control web app in your browser, as shown on page 14. If not visit Appendix A, “Troubleshooting” page (77).

Obtaining IP address for your 24Ai or 24Ao

On the front panel of the interface, push the ID button once. The LCD now displays the unit's IP address, which should look something like this: "IP Address: 192.168.1.209".

DEVICE TAB

6 7 8 9 10 11 MOTU Device Routing Mixing Aux Mixing 24AI New Update Available (1.2.4B1) More info Configuration Sample Rate: 48000 Clock Nodes: Internal Quick Setup Launch Quick Setup Clock Status: Word Clock Out: Follow System Clock Become Clock Master Input Settings Analog Analog 1 Analog 2 Analog 3 Analog 4 Analog 5 Analog 6 Analog 7 Analog 8 Analog 9 Analog 10 Analog 11 Analog 12 Analog 13 Analog 14 Analog 15 Analog 16 Analog 17 Analog 18 Analog 19 Analog 20 Analog 21 Analog 22 Analog 23 Analog 24

Input Settings Analog Analog 1 Analog 2 Analog 3 Analog 4 Analog 5 Analog 6 Analog 7 Analog 8 Analog 9 Analog 10 Analog 11 Analog 12 Analog 13 Analog 14 Analog 15 Analog 16 Analog 17 Analog 18 Analog 19 Analog 20 Analog 21 Analog 22 Analog 23 Analog 24

1. If you have two or more MOTU AVB interfaces, the Device list lets you choose the one you are currently controlling with the web app.
2. The Aux Mixing tab lets you view each Aux bus in the mixer, one at a time.
3. The Mixing tab gives you access to the mixing and DSP in the interface.
4. The Routing tab displays a grid matrix, where you can make direct connections between inputs and outputs, your computer, the mixer, and network audio streams, if networked interfaces are connected.
5. The Device tab has settings for the hardware itself, such as mic input phantom power and preamp gain.

6. Expands and collapses the sidebar.

7. Lets you create, save, recall and manage presets for your MOTU AVB interface. These presets capture and recall the complete state of the device (all settings in all tabs).

8. Choose the desired sample rate.
9. The Quick Setup button prompts factory presets used to configure your interface for a specific application. See chapter 5, "Presets" (page 47).
10. Click to rename the interface. To restore the default name, delete the current name.

11. Click this device ID button to identify the unit you are currently viewing and controlling with the web app software. The front panel LCD on the hardware itself will flash the name of the device, and its name will also flash in the Device list (1).

12. If an update is available for your device, and the computer you are viewing it from is connected to the internet, you'll be notified here. Click More Info to learn what's new and start the update process. Firmware updating requires a network connection. See Appendix E, "Updating Firmware" page (87).

13. Choose the clock source from the Clock Mode menu. Your MOTU device will resolve its digital clock to this master source. See "Synchronization" on page 40.

14. Indicates that the current device (1) is successfully resolved to its chosen Clock Mode source (13). If it cannot lock for some reason, this icon flashes red. Check your chosen clock source, cables, etc.

15. At higher sample rates, the Word Clock Out can either follow the system clock or operate at the corresponding 1x sample rate. For details, see "Follow system clock / Force 1x clock" on page 42.

16. If you have multiple MOTU AVB interfaces, one of them may serve as a master clock source for the network. Click this button to choose the current interface (1) as the master clock source.
17. These are the Output Settings for the 24Ao, which provide 32 bit trim in the DACs from zero to -24 dB.
18. These are the Input Settings for the 24Ai, which provide digitally controlled analog trim from -96 to +22 dB.

DEVICE TAB (CONTINUED)

19 20 AVB Stream Setup Number of Input Streams: 2 out of 4 Number of Output Streams: 2 out of 8 AVB Stream Connections Input Stream 1: 16A3 Input Stream 2: 16A2 Input Banks Enable or Disable Input Banks Analog Optical A Optical B Optical C Output Banks Enable or Disable Output Banks Optical A Optical B Optical C Mixer Setup Number of Inputs: 48 out of 48 Optical Setup Format 2x Output Name Standard Inputs Optical A: ADAT Output Optical A: TOSLink Computer Setup From device to computer: 24 out of 24 From computer to device: 24 out of 24 Reboot Device Reboot Factory Presets Feature Facility Presets Update Device Check for Updates Update From File System Information Manufacture Model QUID Firmware Version U Version Hardware MOTU 2UN 00015R000/21c 1.1.4*543 1.1.6*4995 CH024A

Scroll down to view these additional Device tab settings.

1. In the Input/Output Banks sections, you can disable any banks that you are not using. Doing so hides them from the routing matrix and mixer to simplify operation. Doing so also helps conserve DSP resources.
2. AVB is IEEE's Audio Video Bridging Ethernet standard for high-bandwidth, low-latency audio streaming over Ethernet. If your 24Ai or 24Ao is connected to a 2nd MOTU AVB interface through its network port, or to an AVB switch for access to an extended AVB network, you can stream audio channels to

other destinations on the network. AVB streams are handled in banks of eight channels, so if you enable 8 out of 8 streams, that's 64 channels. See chapter 9, "Networking" (page 69).

1. If you have AVB network input streams enabled, connect them to the output streams of other devices on the network here.

2. In the Computer Setup section, you can specify how many audio channels you would like to be able to stream to and from your computer, up to 24 channels each way, simultaneously. Map them as desired in the Routing tab (page 16).

3. Use these buttons to manually check for and install updates for your MOTU AVB device. For complete details, see Appendix E, "Updating Firmware" page (87). Updating from a file can be done offline from your computer, using an update you've obtained through MOTU's web site or tech support department. The Check For Updates button requires that the computer (or device) you are using to view your MOTU AVB interface is connected to the internet through a local network or WiFi. Updating from the internet is easy and convenient.

4. Use these buttons to reboot (restart) the device, or restore its factory presets.

5. In the Optical Setup section, you can choose between 8-channel ADAT or stereo TOSLink formats for bank A input and output, independently. At 882. or 96 kHz, the ADAT setting supports 4-channel SMUX format. For details, see "Optical" on page 40.
6. The digital mixer in your MOTU AVB interface supports up to 48 channels. If you don't need that many inputs, you can lower the number here to simplify mixer and routing operation and conserve DSP bandwidth for effects processing.

ROUTING TAB

1 2 3 4 5 6 7 8 9 10 Inputs From Computer ADAT A ADAT B ADAT C From Computer 1 From Computer 2 From Computer 3 From Computer 4 From Computer 5 From Computer 6 From Computer 7 From Computer 8 From Computer 9 From Computer 10 From Computer 11 From Computer 12 From Computer 13 From Computer 14 From Computer 15 From Computer 16 From Computer 17 From Computer 18 From Computer 19 From Computer 20 From Computer 21 From Computer 22 From Computer 23 From Computer 24 AVB Stream 1 AVB Stream 2 Mix Main Mix Monitor Mix Aux Mix Group Mix Research Mix Post FX Output Source Analog 1 From Computer 1 Analog 2 From Computer 2 Analog 3 From Computer 3 Analog 4 From Computer 4 Analog 5 From Computer 5 Analog 6 From Computer 6 Analog 7 From Computer 7 Analog 8 From Computer 8 Analog 9 From Computer 9 Analog 10 From Computer 10 Analog 11 From Computer 11 Analog 12 From Computer 12 Analog 13 From Computer 13 Analog 14 From Computer 14 Analog 15 From Computer 15 Analog 16 From Computer 16 Analog 17 From Computer 17 Analog 18 From Computer 18 Analog 19 From Computer 19 Analog 20 From Computer 20 Analog 21 From Computer 21 Analog 22 From Computer 22 Analog 23 From Computer 23 Analog 24 From Computer 24 ADAT A ADAT B ADAT C To Computer AVS Stream 1 AVS Stream 2 Mix In

The Routing Tab lets you route inputs to outputs. Outputs are listed by row on the left; inputs are listed in columns across the top. Simply click in the grid to make a single connection. Click and drag to make multiple connections in one gesture. To route a single input to multiple outputs, make multiple connections vertically in the same column below the input. To mix multiple inputs to the same output, you'll need to use the mixer (page 17) and the Mix In bank in the routing tab (16).

1. In its collapsed form, (shown here), the sidebar displays icons for each tab.
2. Click this icon to view the Routing tab, shown on this page.
3. Click here to show or hide the sidebar.
4. Create, save, recall and manage routing presets.

5. Outputs are listed in rows on the left.

6. When you make a connection, the source (input) signal is listed by name here in the Source column, just to the right of the output it is being routed to.

7. Inputs are listed in columns across the top of the grid, starting with the physical inputs on the hardware itself. In this example, each 8-channel ADAT optical bank is collapsed. In the grid below, in the first column, you can see that Bank A input is routed to the computer.
8. The From Computer input bank lets you route audio channels from your host audio software to any output, including AVB network streams or the mixer. In this example, all 24 computer output channels are routed to the 24Ao analog outs. Use the Device tab to choose how many computer channels are available.
9. AVB streams are 8-channel banks that let you route audio to or from other devices on the AVB network (if any are connected) to local hardware inputs and outputs. Use

the Device tab (page 15) to configure how many AVB streams you wish to work with. If you aren't working with network audio, you can set the number of streams to zero.

1. These input streams are busses that originate from the mixer, which supplies the main mix bus, monitor mix bus, seven stereo aux busses, three stereo group busses, a reverb return bus and postFX channel sends (for sending processed inputs to the computer or elsewhere). You can route these mixer busses to any outputs you wish (5), including physical outputs, host software on your computer, other devices on the AVB network, or even back in to the mixer (beware of feedback loops!)
2. Use these triangles to expand or collapse groups of inputs. For example, it might be convenient to collapse banks that you are not using at the moment.
3. Click a channel label to rename it.

4. Audio activity indicators.

5. Click the grid to make a connection. Click a connection to remove it. Click and drag to make or break multiple connections in one gesture.

6. In this example, all 24 channels from the computer are routed to the 24 analog outputs on the 24Ao. In addition, all 24 computer channels are simultaneously being routed to the three ADAT banks, for 24 channels of digital output.
7. The Mix In group lets you route audio to the 48-channel mixer.
8. These AVB output streams let you route any audio to other devices on the AVB network.
9. The To Computer output bank routes any input to host audio software running on your computer. Use the Device tab to choose how many computer channels are available.
10. Use these triangles to expand or collapse groups of outputs.
11. These are the physical outputs on the interface itself.

MIXING TAB

CONTROLS Legend High Pass Filter Gate EQ Compressor Aux Sends Group Sends MIXER INPUTS In 1 In 2 In 3 In 4 In 5 In 6 In 7 In 8 MIXER OUTPUTS Group 1-2 Group 3-4 Group 5-6 Reverb Aux 1-2 Aux 3 Aux 4 Aux 6 Aux 7-8 Aux 8-10 Aux 11-12 Aux 13-14 DBP Linger Gate Comp Therap Audio Level Aux Reduction Solid Clear Group Sends Group 1-2 Group 3-4 Group 5-6 Reverb Aux 1-2 Aux 3 Aux 4 Group Sends Group 1-2 Group 3-4 Group 5-6 Group 8-10 Group 11-12 Group 13-14 In 1 In 2 In 3 In 4 In 5 In 6 In 7 In 8 In 9 In 10 In 11 In 12 In 13 In 14 In 15 In 16 In 17 In 18 In 19 In 20 In 21 In 22 In 23 In 24 Group 1-2 Group 3-4 Group 5-6 Group 8-10 Group Sends Group 1-2 Group 3-4 Group 5-6 Group 8-10 Group Sends Group 1-2 Group 3-4 Group 5-6 Group 8-10 Group Sends

The Mixing tab gives you full access to the 48-channel mixer in your MOTU AVB interface, which provides a main mix bus, monitor bus, three group busses, seven aux busses, and a dedicated reverb bus. Use the Device tab to configure how many inputs you wish to work with (up to 48). Use the Routing tab (page 16) to route channels to the mixer inputs. Channels can come from any source, such as the physical inputs on the interface, channels coming from the computer, or channels coming from the AVB network.

1. Shows and hides the Mixer Setup sidebar (3), which lets you show and hide channels, channel strip settings, effects, and the Legend (6).
2. The Mixing tab selects the mixer.
3. Use the Mixer Setup sidebar to show and hide elements in the mixer.
4. Shows and hides all elements in the section with one click.

5. Create, save, recall and manage mixer presets.

6. This column is the Legend. It provides labels and controls for channel strip sections. The menu at the top lets you create, name, save and manage entire mixer presets.

7. Mixer input channels.
8. This input channel has its Gate and Compressor enabled. Disabled effects are grayed out.
9. This is Group bus 1-2. You can send inputs to this group with their Group send fader (24). Groups are sent to the Main Mix with its Main send fader (24) or aux busses (19).
10. Group buses, the main mix bus, and the reverb return bus are equipped with the Leveler, a vintage compressor modeled after the Teletronix LA-2A leveling amplifier.
11. The reverb channel strip provides controls for the reverb processor. Use the reverb send on individual inputs or groups to route them to the reverb bus, which can then be mixed

in with the main mix or aux busses. Disable the reverb processor to use it as an extra group.

1. The Monitor Bus can mirror the output of any other bus, or it can act as a separate Solo bus. See page 20.
2. The Main Mix bus is the master fader for the entire mixer. You can add EQ and Leveler compression.
3. You can adjust Aux bus output levels here, or in the Aux Mixing tab shown on page 18.
4. Click a name to change it, except for the Main Mix, Monitor, and Reverb busses, which cannot be changed.
5. Stereo toggle to switch channels pairs between mono or stereo. Use the other menus to manage channel strip presets and to choose audio sources and destinations for mixer inputs and bus outputs.
6. Gate processing for inputs.

7. The Dynamics section provides a conventional compressor for inputs and the Leveler for output busses.

8. Reverb and aux sends.

9. Solo and mute. On the Monitor bus, the SC button clears all solos.
10. Channel faders.
11. Choose the source for the Monitor bus from this menu. It can mirror any output bus or the Solo Bus.
12. When Follow Solo is enabled, the Monitor bus temporarily switches to the solo bus when any channel is soloed.
13. Group sends.
14. 'S' lets you solo the group. 'PRE' toggles the sends between pre- and post-fader routing, i.e. before or after the channel fader.
15. Show and hide output busses here.
16. Show/hide all busses with one click.
17. Same as (25) above.
18. Show and hide inputs here.
19. Show/hide all inputs with one click.

AUX MIXING TAB

AUX MIX TARGET Aux 1-2 Aux 3 Aux 4 Aux 5-6 Aux 7-8 Aux 9-10 Aux 11-12 MIXER INPUTS In 1 In 2 In 3 In 4 In 5 In 6 In 7 GROUPS Group 1-2 Group 3-4 Group 5-6 Reverb In 1 In 2 In 3 In 4 In 5 In 6 Groups Pretader View Personal Mix In 1 In 2 In 3 In 4 In 5 In 6 Reverb In 2 In 3 In 4 In 5 In 6 Reverb In 4 In 5 In 6 Reverb In 2 In 3 In 4 In 5 In 6 Reverb In 1 In 2 In 3 In 4 In 5 In 6 Reverb

The Aux Mixing tab provides quick access to your MOTU AVB interface's mix busses (aux busses, groups and reverb bus), viewed one at a time. Choose a bus in the Aux Mix Target section and then use the faders to directly mix the send levels from all mixer inputs, groups, and the reverb bus.

1. Shows and hides the Mixer Setup sidebar (3), which lets you show and hide channels.

2. The Aux Mixing tab (shown on this page) gives you access to the Aux busses and groups in the mixer.

3. Use the Aux Mix Target sidebar to control which aux bus or group you are currently viewing. You can also show/hide inputs and group sends.

4. Click the aux bus or group you wish to view in the window. In this example, Aux bus 1-2 is being displayed.

5. These are mixer inputs (aux sends from each mixer channel). To include an input in the aux bus mix, simply bring up its fader.

6. These are group bus faders.

7. This is the mixer's reverb bus fader.

8. This is the master fader for the current aux bus being viewed (4).

9. Indicates if the input or group is stereo or mono. Each channel's mono/stereo status cannot be toggled (unlike MIXING page).

10. Solo and mute for the aux bus master fader.

11. When Prefader is enabled, all send levels to the aux bus are independent of the main fader for each channel. In other words, changing an individual channel's main fader in the Mixing tab won't affect its send level to the aux bus.

12. Click the View Personal Mix button to open a new web page that displays only that specific Aux Mix or Group.

13. Show and hide mix groups and the reverb bus here.

14. Use the Groups button here to show or hide all groups with one click.

15. Show and hide mixer inputs (channel sends) here.

16. Show and hide all mixer inputs with one click here.

MIXER INPUT CHANNEL STRIPS

1 2 4 5 6 7 8 9 From Computer 1 Name ADAT A (0) ADAT B (0) ADAT C (0) From Computer (24) From Computer 1 From Computer 2 From Computer 3 From Computer 4 From Computer 5 From Computer 6 From Computer 7 From Computer 8 From Computer 9 From Computer 10 From Computer 11 From Computer 12 From Computer 13 From Computer 14 From Computer 15 From Computer 16 From Computer 17 From Computer 18 From Computer 19 From Computer 20 From Computer 21 Group Sends Group 1-2 Group 2-4 Group 3-6

To access a mixer input channel strip, go to the Mixing tab (page 17), reveal the side bar (item #3 on page 17), and then show the input channel you want in the Mixer Inputs section (29).

To show and hide sections of the channel strip, such as EQ or the compressor, use the Controls section of the side bar (item #3 in the Mixing tab on page 17).

1. Click the input channel name to change it. Delete the current name to restore the default name.
2. Provides hardware settings for inputs, if any, on other MOTU AVB interfaces. In the case of the 24Ai and 24Ao, this is grayed out because there are no hardware settings for inputs.
3. Choose the source for the input channel. You can also make this setting directly on the Routing grid (page 16).
4. Create, name, save and recall channel strip presets.
5. Toggles the input between mono and a stereo pair.
6. High Pass Filter with cutoff frequency.
7. Each effect in the channel strip (High Pass Filter, Gate, EQ, etc.) has an on/off button (on the left) and a preset menu on the right, for managing presets that apply only to that processing module. For example, you can create your own EQ presets for the EQ modules.
8. The Gate processor provides standard attack, threshold and release controls.
9. The Gate indicator turns red when the gate is engaged.
10. The EQ section provides four bands of parametric EQ, each with standard Gain, Frequency, and Bandwidth settings.
11. The High and Low EQ bands provide a Shelf filter button for standard high and low shelf filtering.
12. The Compressor provides standard controls for Threshold, Ratio, Attack, Release and Gain. Normally, the compressor operates in Peak mode, where signal peaks determine the

input level. Engage the RMS button to uses RMS values (a computational method for determining overall loudness) to measure the input level.

1. Input level and gain reduction meters for the compressor.
2. Aux and reverb sends.
3. Solo/Mute. Mute affects all sends as well as the main channel. Pre-fader sends are not affected by Mute.
4. Move the fader to adjust level. Double-click to return to zero (unity gain) or - .
5. Click the dB scale numbers to make the fader jump exactly to that level. Click and drag horizontally to jump consecutive faders to the same level.
6. Click to type in an exact dB level.
7. Channel pan. For mono inputs, double-click to center.
8. Main Mix Slider is used to feed signal to the Main Mix. Slider is set to 0 dB by default, so all channel strips are pre-routed to the Main Mix bus. If a channel is being sent to a Group (which will eventually be fed to the Main Mix), drag the slider to -∞ so it is not sent to Main Mix directly.
9. Group sends.
10. 'S' lets you solo the group. 'PRE' toggles the sends between pre- and post-fader routing, i.e. before or after the channel fader.
11. Clears all solos.
12. 'S' lets you solo the Aux bus. 'PRE' toggles the sends between pre- and post-fader routing, i.e. before or after the channel fader. The dots let you toggle the Aux bus between mono and stereo.
13. This side bar, with the section labels in it, can be shown or hidden using the Legend switch in the Controls section of the side bar (item #3 in the Mixing tab on page 17).
14. Shows how much DSP power is being used by the mixer hardware. To free up DSP bandwidth, try reducing the number of mixer ins, disabling channel effects, reverb, etc. See "DSP Usage" on page 68 for more info.

MAIN MIX AND MONITOR CHANNEL STRIPS

Monitor Main Mix High Gize Freq Shelf Mid Gize Freq Randomize Mid Gize Freq Randomize Low Gain Freq Shell Leveler Reduction Makeup Limit Gain Reduction 14 3 5 6 Analog 1 Analog 2 Trim Trin To a cha (pa) right To s strip Con the 1. B 2. T 3. P 4. U 5. U 13 SC M M -16.1 dB -8.8 dB 9 10 12 Solo Bus Follow Solo

Main None Analog (12) Analog 1-3 Analog 3-4 Analog 5-6 Analog 7-8 Analog 9-10 Analog 11-12 Analog 13-14 Analog 15-16 Analog 17-18 Analog 19-20 Analog 21-22 Analog 25-24 ADAT A (4) ADAT B (4) ADAT C (4) To Computer (1)

5 Store Delete Add Create new channel project Storage Presents Import Edit Remove Save Delete Balance Forward Pressets

To access the Main Mix and Monitor channel strips, go to the Mixing tab (page 17) and scroll the display to the right, beyond the inputs and groups.

To show and hide sections of the channel strip, such as EQ or the Leveler, use the Controls section of the side bar (item #3 in the Mixing tab on page 17).

1. By default, the Monitor bus serves as a solo bus. However, it can be set to mirror the main mix bus, or any other aux bus, group, or the reverb bus, in addition to monitoring solo. Make this choice in the source menu (12). Use the Routing grid (page 16) to specify the output for the Monitor bus.
2. The Main Mix bus is the primary stereo mix.
3. Provides hardware settings for any assigned outputs that have them. For example, if the Main Mix bus is assigned to analog outputs on the 24Ao, you'll see trim settings for the outputs. This item is grayed out if there are no hardware settings for output.
4. Use this output assignment widget to choose the destination — or multiple destinations — for the bus. You can also make this setting directly on the Routing grid (page 16).

5. Use the preset menus to create save, recall, and otherwise manage channel strip presets for the Monitor bus and Main Mix bus.

6. Indicates that the bus is stereo.

7. The four-band parametric EQ for the Main Mix bus operates the same as described for input channels (items 10 and 11 on page 19), including High and Low Shelf filter options.
8. The Leveler provides specialized gain reduction modeled after the legendary Teletronix LA-2A Leveling Amplifier. For complete details, see "Leveler" on page 66.
9. Mutes for the Main Mix bus and Monitor bus.
10. Master faders for the Main Mix bus and Monitor bus. Use the same techniques described for input channel faders (items 16, 17 and 18 on page 19).
11. When Follow Solo is enabled, the Monitor bus switches to the solo bus when any channel is soloed. NOTE: if an aux bus is soloed, then the Monitor bus carries only the soloed aux bus (any current channel solos are excluded).
12. Choose the source for the Monitor bus from this menu. It can mirror the main mix, any aux bus, group, the reverb bus, or it can serve only as a Solo bus.
13. The SC button clears all solos.
14. This mid-band EQ is currently disabled (and therefore grayed out).

AUX BUS CHANNEL STRIPS

Aux 1-2 Aux 3 Aux 4 High Gain Freq Shelf High Gain Freq Shelf Mid Gain Freq Bandwidth Mid Gain Freq Bandwidth Mid Gain Freq Bandwidth Mid Gain Freq Bandwidth Low Gain Freq Shelf Low Gain Freq Shelf S M S M S M +4.6 dB -3.9 dB -12.8 dB

Aux busses can be used to create sub-mixes. An aux bus can be assigned to any output in the Routing grid (page 16).

To access an Aux bus channel strip, go to the Mixing tab (page 17), reveal the side bar (item #3 on page 17), and then show the aux busses you want in the Mixer Outputs section (26).

To show and hide the four-band EQ section of the channel strip, use the Controls section of the side bar (item #3 in the Mixing tab on page 17).

1. A stereo aux bus.
2. A mono aux bus.
3. Click this dot to toggle an aux bus between mono and stereo.
4. The four-band parametric EQ module for Aux busses operates the same as described for input channels (items 10 and 11 on page 19), including High and Low Shelf filter options.
5. Aux bus solo and mute.
6. Aux bus master fader.
7. Click to type specific value manually.
8. Click the dB scale numbers to make the fader jump exactly to that level. Click and drag horizontally to jump consecutive faders to the same level.
9. A disabled EQ band.
10. Use these menus (hardware settings, output assignment, and presets) in a similar fashion as described for the Main Out bus (items 3-5 on page 20).

GROUP AND REVERB CHANNEL STRIPS

Group 1-2 Group 3-4 Reverb High Gain Freq Shelf High Gain Freq Shelf Mid Gain Freq Bandwidth Mid Gain Freq Bandwidth Mid Gain Freq Bandwidth Mid Gain Freq Bandwidth Low Gain Freq Shelf Low Gain Freq Shelf Leveler Reduction Makeup Gain Gain Reduction Leveler Reduction Makeup Gain Reduction Leveler Reduction Makeup Gain Reduction Reverb Reverb S M S M S M Reverb Reverb Time Mec Pseudo Cspread High Ratio Mid Ratio Main Main Main

Group busses can be used to create a mix subgroup, which is a set of inputs you wish to control together as a group. Groups differ from aux busses in that they have aux sends, a reverb send, as well as a main mix send. In addition, group busses are equipped with the Leveler.

The Reverb bus is a special group bus that provides a reverb processor. If you disable the reverb, the reverb bus functions as a (fourth) regular group bus.

To access the Group and Reverb bus channel strips, go to the Mixing tab (page 17), reveal the side bar (item #3 on page 17), and then show the desired Group busses or Reverb bus in the Mixer Outputs section (26).

To show and hide the four-band EQ section of the channel strip, use the Controls section of the side bar (item #3 in the Mixing tab on page 17).

1. A Group bus channel strip. Click the name to rename it. Delete the current name to return to its default.
2. The Reverb bus. If you disable the Reverb processor, it can be used as a fourth Group bus. The Reverb channel strip is twice as wide as other mixer channel strips to accommodate the Reverb processor controls.
3. Group busses and the Reverb bus are always stereo.
4. The four-band parametric EQ module for Group busses and the Reverb bus operates the same as described for input channels (items 10 and 11 on page 19), including High and Low Shelf filter options.
5. The Reverb processor. For complete information, see "Reverb" on page 67.
6. Main Mix sends.
7. Master faders for the Group and Reverb busses.
8. Mute and Solo.
9. Use these menus (hardware settings, output assignment, and presets) in a similar fashion as described for the Main Out bus (items 3-5 on page 20).

CHAPTER 1 About Your MOTU AVB Audio Interface

The 24Ai and 24Ao are hybrid USB2/AVB audio interfaces with 48-channel digital mixers and AVB Ethernet networking capability. They can operate as audio interfaces for a computer, as stand-alone digital mixers, as gateways to an expanded studio system, as components of an extended AVB audio network, or as capable hybrid devices performing all of these roles simultaneously.

Together, they are designed to be a central component of a modern, high performance recording studio or live mixing platform. The following sections provide a brief overview of their main features and characteristics.

State-of-the-art A/D and D/A conversion

The analog section of each interface employs state-of-the-art 24-bit DACs or ADCs, which deliver analog recording and playback with remarkably high dynamic range at sample rates from 44.1 to 192 kHz.

Complementary I/O configurations

Each interface delivers an exceptional amount of analog and digital audio. In addition, the interfaces are designed to complement each other, and MOTU's other AVB-equipped audio interfaces, to deliver a wide range of I/O options; you can mix and match several interfaces and operate them as a unified I/O and mixing system. The following sections provide a bird's-eye glance of the I/O configurations offered by each interface in the MOTU AVB family.

Each interface provides a variety of analog and digital interconnects, all active simultaneously, designed to provide everything you need for a well-equipped recording studio.

24Ai

72 simultaneous audio channels

Connection Input Output

Balanced analog on 3x D-sub or 6x Phoenix 24 -

ADAT optical digital (at 44.1 or 48 kHz) 24 24

Total 48 24

24Ao

72 simultaneous audio channels;

Connection Input Output

Balanced analog on 3x D-sub or 6x Phoenix - 24

ADAT optical digital (at 44.1 or 48 kHz) 24 24

Total 24 48

Network I/O

Each interface is also capable of handling additional 8-channel banks of network audio input and output for an additional 96 simultaneous audio channels.

Other MOTU AVB interfaces

The 24Ai and 24Ao are part of a larger family of audio interfaces, summarized below, with complementary I/O configurations.

1248

66 simultaneous audio channels

Connection Input Output

Quarter-inch analog on bal/unbal TRS 8 12
Mic inputs with individual preamps on XLR 4 -
Hi-Z guitar inputs	2 -
Headphone output	- 2 x stereo
ADAT optical digital (at 44.1 or 48 kHz) 16 16
RCA S/PDIF digital up to 96 kHz with SRC	stereo stereo

Total 32 34

8M

50 simultaneous audio channels

Connection Input Output

Quarter-inch analog on bal/unbal TRS - 8

Mic/guitar inputs on combo XLR/TRS 8 -

Headphone output - stereo

ADAT optical digital (at 44.1 or 48 kHz) 16 16

Total

24 26

16A

64 simultaneous audio channels

Connection Input Output

Quarter-inch analog on bal/unbal TRS 16 16

ADAT optical digital (at 44.1 or 48 kHz) 16 16

Total

32 32

Universal connectivity

The 24Ai and 24Ao can connect to a computer with high-speed USB 2.0, which is compatible with USB 3.0). They are USB audio class-compliant, which means that they are iPad compatible (with a camera connection kit) and do not require driver installation for USB connection to a computer.

Alternately, the 24Ai and 24Ao can be connected to the Ethernet port on a recent-generation Mac (any Mac with Thunderbolt on it) running Mac OS X Yosemite (10.10) or later for audio interface operation through AVB Ethernet.

On-board DSP with mixing and effects

Each interface is equipped with a powerful DSP engine that drives both an extensive routing matrix and a 48-input digital mixer with 12 stereo busses and effects. The mixer offers familiar operation modeled after large format mixing consoles.

32-bit floating point processing

All of the mixing and effects processing in the DSP engine is handled with 32-bit floating point calculations, to maintain and deliver virtually unlimited headroom and the utmost in sound quality.

Modeled vintage effects processing

Effects include “classic” reverb, compression modeled after the legendary Teletronix LA-2A compressor, and 4-band EQ modeled after British analog console EQs.

AVB system expansion and audio networking

AVB stands for the IEEE 802.1 Audio Video Bridging Ethernet standard for high-bandwidth, low-latency audio streaming over Ethernet. The AVB Ethernet network port on each MOTU interface lets you add a second AVB-equipped MOTU interface using any standard CAT-5e Ethernet cable. You can network up to five MOTU interfaces together using a MOTU AVB Switch™ (sold separately), and then run them as a standalone network or as an extended bank of I/Os for your computer-based production system (or both). You can even connect multiple computers, each with full access to all devices on the network (including the other computers).

With additional standard AVB switches (from MOTU or other brands) and standard Ethernet cabling, you can build an extensive AVB audio network. The entire network operates with near-zero network latency, even over very long cable runs. MOTU's AVB implementation allows you to stream hundreds of audio channels among devices and computers on the network with guaranteed Quality of Service (QoS), prioritizing audio streams over less important traffic.

Matrix routing and multing

Each MOTU interface provides completely flexible matrix-style audio routing and multing. You can route any analog or digital input, computer

channel, or network stream to any other output, computer, or network device. You can also mult any single input to unlimited multiple output destinations.

24 channels of network audio I/O for your host computer

The 24Ai and 24Ao let you stream up to 24 audio channels in and out, simultaneously, through their USB connection to a host computer. Sources and destinations can include inputs and outputs on the device, inputs and outputs on other interfaces on the network, and even audio software apps running on other computers connected to other devices on the network.

Web app control

You can control on-board DSP, mixing, device settings, clock/sync settings, and network audio routing from the MOTU AVB Control web app software running in your favorite browser on a laptop, tablet or smart phone connected to your MOTU interface directly, or through your local WiFi network. Multiple devices can be used simultaneously to access any audio interface settings on the network.

Stand-alone mixing with wireless control

If you connect your MOTU interface to an Apple Airport or other WiFi router with a standard Ethernet cable, you can control its powerful mixing and DSP effects from your smart phone or tablet, without a computer — great for live sound mixing from your iPad, tablet, or other wireless device.

ADAT digital I/O

The 24Ai and 24Ao interfaces each provide three 8-channel banks of optical digital I/O. Connect outboard digital processors, digital mixers or other gear: 24 channels at 44.1/48 kHz or 12 channels at 88.2/96 kHz.

Word clock

Each MOTU interface supports standard word clock synchronization at any supported sample rate. When the interface is operating at 96 kHz, it can generate word clock output at either 96 or 48 kHz; the 1x equivalence is available as an option for word clock output when running at high sample rates (from 88.2 to 192 kHz). The word clock OUT port can alternately be used as a THRU port for word clock daisy-chaining. To configure, use the LCD menu to navigate to Settings -> Word Clock Thru Mode.

Comprehensive metering

The large backlit LCD displays all signal activity at a glance with detailed metering for all analog and digital I/O. You can access many hardware settings directly from the front panel.

Precision Digital Trim™

Analog inputs are equipped with digitally controlled analog trims, adjustable in 1 dB increments. Analog outputs offer 32 bit trim in the DAC, also adjustable in 1 dB increments. You can save your trim configurations as a preset for instant recall.

Rack mount or desktop operation

Each interface is housed in a sturdy, metal-alloy, 19-inch, rack-mountable unit. The rack mounting brackets can be removed using a 7/64" hex wrench for desktop operation.

AudioDesk

AudioDesk is a full-featured audio workstation software package for Mac and Windows that is available as a free download for you as a 24Ai or 24Ao owner. Visit motu.com/avb to obtain your copy. AudioDesk provides multi-channel waveform editing, automated virtual mixing, graphic editing of ramp automation, real-time effects plug-ins with crossfades, support for many third-party audio plug-ins, sample-accurate editing and placement of audio, and more.

CHAPTER 2 Packing List and System Requirements

PACKING LIST

Your MOTU interface ships with the items listed below. If any of these items are not present in the box when you first open it, please immediately contact your dealer or MOTU.

■ One audio interface
■ One USB cable
■ One power cord
■ One manual
■ Product registration card

SYSTEM REQUIREMENTS

■ A 1 GHz Intel-based Mac or Pentium-based PC (or compatible). Faster CPUs are recommended for best performance.

■ 2 GB RAM; 4 GB or more recommended.

■ OS X 10.8 or later; Windows 7 or later; for operation as an AVB Ethernet audio interface, Mac OS X 10.10 or later is required, running on a recent-generation Mac (any Mac with a Thunderbolt port on it).

■ Available high-speed USB 2.0 (or 3.0) port

■ A large hard drive (preferably at least 500 GB)

PLEASE REGISTER TODAY!

Please register your MOTU interface today. There are two ways to register.

■ Visit www.motu.com/register

OR

■ Fill out and mail the included product registration card

As a registered user, you will be eligible to receive technical support and announcements about product enhancements as soon as they become available. Only registered users receive these special update notices, so please register today.

Thank you for taking the time to register your new MOTU products!

CHAPTER 3 Software Installation

OVERVIEW

USB 2.0 class-compliant operation.... 29

Operation as an AVB Ethernet audio interface ..... 29

Software installation.... 29

Audio drivers 30

MOTU AVB Discovery app for Mac 30

MOTU AVB WebUI Setup for Windows 30

MOTU AVB USB Control Panel 30

AudioDesk workstation software.... 31

Working with host audio software 31

USB 2.0 CLASS-COMPLIANT OPERATION

Your MOTU interface is a USB 2.0 audio class-compliant device. This means that you can connect it to your Mac with a USB cable and use it without installing any software drivers. The computer recognizes your MOTU interface as a USB audio device and makes its inputs and outputs available to your host audio software. Basic settings, such as the hardware's sample rate, are made in either your host software (Mac) or your system settings (Windows).

In this scenario, your MOTU interface provides basic audio input and output, and no software driver installation is necessary.

As explained earlier in this guide, the MOTU AVB Control web app provides full access to all settings in the device, including the extensive on-board routing, mixing, and effects processing features. Since the web app is served from the audio interface hardware itself, it does not require any software installation on your computer; all it requires is a network connection between your computer and your MOTU interface with a standard Ethernet cable, Ethernet hub, or shared Wi-Fi network. For details about accessing the web app through the network port, see “MOTU AVB Control Web App” on page 13.

OPERATION AS AN AVB ETHERNET AUDIO INTERFACE

To use your MOTU interface as an audio interface over AVB Ethernet, all you need is a recent Mac (any Mac that has a Thunderbolt port on it) with Mac OS X Yosemite (10.10) or later installed.

Connect the network port on your MOTU interface to the Ethernet port on the Mac using a standard, high-grade (CAT-5e or CAT-6) network cable up to 100 meters in length. You can then use your MOTU interface as a standard, low-latency multi-channel audio interface with any Core Audio compatible host software running on the Mac.

In this scenario, your MOTU interface provides basic audio input and output, and no software driver installation is necessary.

For details about accessing device settings in the web app through a network port connection, see "MOTU AVB Control Web App" on page 13.

SOFTWARE INSTALLATION

Software installation is required for any of the following scenarios:

■ You are using a PC running Windows 7 or later.

■ You will use your MOTU interface as a USB audio interface, and you want to access the web app without the network port.

■ You will be using multiple MOTU interfaces.

If none of the above scenarios apply to you, then you can skip software installation if you wish, and proceed to details about accessing the web app through the network port, see “MOTU AVB Control Web App” on page 13.

Download and run the MOTU AVB Audio Installer

To download the latest MOTU AVB audio installer for Mac or Windows, visit www.motu.com/avb. Follow the directions that the installer gives you.

We recommend that you run the software installer before you connect your MOTU interface to your computer and power it on. This ensures that all driver components are properly installed in your system.

AUDIO DRIVERS

On the Mac, no USB audio driver is installed because your MOTU interface is USB audio class compliant, and USB audio operation is handled by Mac OS X. On Windows, the installer provides USB ASIO and Wave drivers.

MOTU AVB USB ASIO Driver

On Windows, to enable your MOTU interface in your ASIO host software, choose the MOTU AVB USB ASIO driver.

Device Setup MIDI MIDI Port Setup Transport Record Time Max Time Display Video VST Audio System MOTU AVB USB ASIO VST Audio Unit VST Audio System MOTU AVB USB ASIO ASIO Driver Release Data when Application is in Background Input Latency: 9.323 ms Output Latency: 9.323 ms ASIO Guard Latency: 10.647 ms HW Sample Rate: 40.000 Hz HW Pull Up/Down: Off Advanced Options Set to Defaults Winning: 1 Audio Records

Figure 3-1: Choosing the MOTU AVB ASIO driver in Cubase.

MOTU AVB DISCOVERY APP FOR MAC

On the Mac, the MOTU AVB Discovery app is installed in your Mac's applications folder; a shortcut is installed for it, too (as shown on page page 13). It locates all MOTU AVB interfaces connected to the Mac, either directly through USB or on your network, and displays them in a list. Choose an interface to access its settings through the web app ("MOTU AVB Control Web App" on page 13).

MOTU AVB WEBUI SETUP FOR WINDOWS

On Windows, the installer provides a MOTU AVB WebUI Setup shortcut found on the Windows desktop or in Start menu> All Programs>MOTU. Use this shortcut to access the MOTU AVB Control web app directly in your favorite web browser.

MOTU AVB USB CONTROL PANEL

On Windows, the MOTU AVB USB Control Panel (Start menu> All Programs> MOTU) provides three tabs: Status, Buffer Settings and Info. The Buffer Settings tab provides several basic settings for the AVB USB driver.

MOTU AVB USB Audio Control Panel Status Buffer Settings Info USB Streaming Mode Standard Asia Buffer Size 256 samples

Figure 3-2: The MOTU AVB USB Audio Control Panel Buffer Settings tab.

USB Streaming Mode

USB Streaming Mode (Figure 3-2) determines how frequently the USB driver transfers audio. Smaller settings reduce latency. This setting determines the latency for standard Windows audio applications (such as Media Player). For further information about latency, see “Reducing monitoring latency” on page 59.

ASIO Buffer Size

ASIO Buffer Size (Figure 3-2) determine how much delay you hear when monitoring live inputs through your audio software: larger buffers produce more delay; smaller buffers produce less. For complete information about this setting, see "Working with Host Audio Software" on page 55.

AUDIODESK WORKSTATION SOFTWARE

AudioDesk is an advanced workstation software package that lets you record, edit, mix, process, bounce and master multi-track digital audio recording projects. Advanced features include real-time effects processing, recording, and much more.

See the AudioDesk User Guide, available on your computer hard drive as a PDF document.

12/31/174* 0:00:23:05 Sub Timeframe Timing Sub Timeframe Track Volume Speed Balance Balance Sheet Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Audio Video

Figure 3-3: AudioDesk.

WORKING WITH HOST AUDIO SOFTWARE

For further information about using your MOTU interface with host audio software, see “Working with Host Audio Software” on page 55.

CHAPTER 4 Hardware Installation

OVERVIEW

Rack installation and heat 33

USB audio interface setup 33

AVB Ethernet audio interface setup.... 34

Setup for two interfaces 34

Setup for three to five interfaces 35

Setup for a multi-switch network.... 36

Setup for multiple interfaces.... 37

Setup for web app control 38

Audio connections.... 40

Synchronization.... 40

Syncing optical devices 41

Syncing word clock devices.... 41

Syncing an AVB network.... 42

Syncing multiple AVB audio interfaces connected to a Mac ....43

RACK INSTALLATION AND HEAT

When installing your MOTU audio interface in a 19-inch rack, leave extra space above, below, behind and on either side of the unit to provide adequate ventilation and heat dispersion. Do not install it near other gear that generates excessive heat.

USB AUDIO INTERFACE SETUP

HI-SPEED USB

Use this setup if you want to use your MOTU device as an audio interface.

■ Use a standard USB cable.

■ Connect to any USB port (USB2.0 or 3.0).

- See “USB2.0 class-compliant operation” on page 33.

■ No driver installation is necessary (unless you want to use the web app).

AVB ETHERNET AUDIO INTERFACE SETUP

IEEE 802.1 AVB

Use this setup if you want to use the 24Ai or 24Ao as an AVB Ethernet audio interface for a recent-generation Mac (i.e. any Mac with a Thunderbolt port on it). Mac OS X Yosemite (10.10) or later is also required for AVB audio I/O.

■ Use a standard CAT-5e or CAT-6 cable.
■ Connect to the computer's Ethernet port.
■See "Operation as an AVB Ethernet audio interface" on page 29.
■ No driver installation is necessary.
■ Enable at least one AVB stream (item #19 on page 15).
- Launch the Mac's Audio MIDI Setup utility to enable the 24Ai or 24Ao and set the clock source and sample rate.
■The number of AVB audio channels that OS X can handle depends on the speed of your Mac.
■ If applicable, see “Syncing multiple AVB audio interfaces connected to a Mac” on page 43.

About CAT-5e cables

Use shielded CAT-5e or CAT-6 cables, which are a higher grade version of a standard Ethernet cable. They are available wherever network cables are sold.

SETUP FOR TWO INTERFACES

graph TD
    A["Laptop"] -->|OR| B["Hi-SPEED USB"]
    B --> C["Server"]
    C --> D["IEEE 802.1 AVB"]
    note["Thunderbolt is available on other MOTU AVB-equipped interfaces, such as the 1248, 8M, 16A and 112D."]]

Use this setup if you want to connect two MOTU interfaces to your computer.

■The connection to the computer can be either USB or Thunderbolt, if you have a Thunderbolt-equipped MOTU AVB interface such as the 1248, 8M, 16A or 112D.
■ Use a standard Thunderbolt cable. Place it at the end of the Thunderbolt chain.
■ Use any standard CAT-5e Ethernet network cable to connect the two interfaces together using their NETWORK ports.
■ As an alternative, see “Setup for multiple interfaces” on page 37.

SETUP FOR THREE TO FIVE INTERFACES

Use this setup if you want to connect three to five MOTU interfaces to your computer using a MOTU AVB Switch ^™ (sold separately).

■ The connection to the computer can be USB or Thunderbolt (if you have a Thunderbolt-equipped MOTU AVB interface). Use Thunderbolt, if possible, to support a large number of audio streams to and from the networked interfaces. A single Thunderbolt connection supports 128 channels in and out, simultaneously. If you need more channels, and your computer has another available Thunderbolt or USB port, you can make a second connection, with full access to the network from both ports.

■ Use standard CAT-5e Ethernet network cables to connect the interfaces to the MOTU AVB Switch using their NETWORK ports.
■ Use the five AVB NETWORK ports on the switch (not the Ethernet port).
■ Network cable lengths can be long: 100 meters with standard copper wire cables; much longer with fiber-optic network cables.
■ See “About CAT-5e cables” on page 34.
■ As an alternative, see “Setup for multiple interfaces” on page 37.
■ To add more computers to the network, connect them to any interface, as shown. All computers and interfaces have full access to each other.
■ See chapter 9, “Networking” (page 69).

graph TD
    A["Desktop"] -->|OR HI-SPEED USB| B["Server"]
    B --> C["IEEE 802.1 AVB"]
    C --> D["MOTU AVB SWITCH"]
    D --> E["Server"]
    F["Thunderbolt"] --> G["IEEE 802.1 AVB"]
    G --> D
    H["Other Devices"] --> I["Server"]
    I --> J["IEEE 802.1 AVB"]
    J --> D
    style A fill:#f9f,stroke:#333
    style F fill:#ccf,stroke:#333
    style H fill:#cfc,stroke:#333
    style B fill:#ffc,stroke:#333
    style C fill:#fcc,stroke:#333
    style D fill:#cff,stroke:#333
    style E fill:#ffc,stroke:#333
    style J fill:#cfc,stroke:#333
    style I fill:#cfc,stroke:#333

SETUP FOR A MULTI-SWITCH NETWORK

Use this setup if you want to connect more than five MOTU interfaces to an extended network that employs multiple AVB switches. AVB Ethernet is an industry standard, so you can use MOTU AVB Switches or 3rd-party AVB switches.

- You can daisy-chain switches in serial fashion, but don't create loops. For example, switches A, B, and C below are chained properly, but don't connect C back to A. Alternately, you could connect both Switches B and C to Switch A.

■ For further information, see chapter 9, "Networking" (page 69).

graph TD
    subgraph_Switch_A["Switch A"]
        A1["Computer"] -->|OR| A2["Hi-SPEED USB"]
        A2 -->|USB| SwitchA["Switch A"]
        A2 -->|USB| SwitchB["Switch B"]
        A2 -->|USB| SwitchC["Switch C"]
        A3["Computer"] -->|OR| A4["Hi-SPEED USB"]
        A4 -->|USB| SwitchB
        A4 -->|USB| SwitchC
        A5["Computer"] -->|OR| A6["Hi-SPEED USB"]
        A6 -->|USB| SwitchB
        A5 -->|USB| SwitchC
    end
    subgraph_Switch_B["Switch B"]
        B1["Computer"] -->|OR| B2["Hi-SPEED USB"]
        B2 -->|USB| SwitchB
        B2 -->|USB| SwitchC
        B3["Computer"] -->|OR| B4["Hi-SPEED USB"]
        B4 -->|USB| SwitchB
        B3 -->|USB| SwitchC
    end
    subgraph_Switch_C["Switch C"]
        C1["Computer"] -->|OR| C2["Hi-SPEED USB"]
        C2 -->|USB| SwitchC
        C1 -->|USB| SwitchA
        C2 -->|USB| SwitchA
    end
    Note: Additional switches, interfaces, and computers are shown on the left. The computer then has access to 128 channels of input and output to the network.

SETUP FOR MULTIPLE INTERFACES

It is possible to connect multiple MOTU interfaces directly to your host computer through multiple USB (and Thunderbolt) ports. Alternately, you can connect multiple interfaces, operating as AVB Ethernet audio interfaces, using an AVB switch connected directly to the Mac. However, there are several disadvantages to using any of these direct connection schemes:

■ The audio interfaces will not be clocked to one another and may be susceptible to drift, unless you use external word clock connections (if available). You are better off using the AVB network connections shown on pages 34-36. In this setup, the interfaces are very tightly synchronized with each other (measured in pico seconds) through their network connections.
■ You will not be able to route audio directly from one audio interface to another. You are better off using the AVB network connections shown on pages 34-36, which allows you to route audio streams (hundreds at a time) directly among interfaces with near-zero latency.

Connecting multiple interfaces using Thunderbolt

If you have other MOTU AVB interfaces with Thunderbolt connectivity (1248, 8M, 16A or 112D) and your host computer has two or more Thunderbolt ports, you can connect one interface to each port, either directly or at the end of a Thunderbolt daisy chain (on either port or both ports).

Connecting multiple interfaces using Thunderbolt and USB

Another way to operate multiple interfaces on the same host computer is to connect the first interface to a Thunderbolt port and the second to a USB 2.0 (or 3.0) port.

Multiple interfaces and USB

When connected through USB, your MOTU interface operates as a USB 2.0 device, even when connected to a USB 3.0 port. USB 2.0 provides enough bus speed for several USB 2.0 devices, but due to your MOTU interface's high-performance requirements for real-time operation and low latency timing, we recommend the following:

• Do not connect more than two units to your computer's USB 2.0 or 3.0 port(s).
• When two units are connected with USB 2.0, don't connect other USB 2.0 or 3.0 devices, such as external hard drives.
  ■ For best results, establish clock synchronization with other interfaces connected to the same computer. You can use optical or AVB to achieve clock synchronization.

Multiple AVB Ethernet audio interfaces

When operating your MOTU interface as an AVB Ethernet audio interface (“AVB Ethernet audio interface setup” on page 34), multiple AVB audio interfaces can be connected using a MOTU AVB Switch (or any 3rd-party AVB switch), and the Mac can see all of them through their AVB connection. For example, you could connect an Avid S3 console to the Mac, and then connect a MOTU interface to the S3’s extra network port (which is a built-in switch). The Mac can see both the MOTU interface and S3 for audio I/O. However, OS X takes over each device for exclusive use, so they can only stream audio to and from the Mac, not each other. The same is true for all AVB devices connected to the Mac. See “Syncing multiple AVB audio interfaces connected to a Mac” on page 43.

Mixing and matching audio interfaces

You can mix and match MOTU audio interfaces. For example, you could connect a 1248 through Thunderbolt and another MOTU audio interface, such as the 24Ao, through USB 2.0.

SETUP FOR WEB APP CONTROL

The MOTU AVB Control web app gives you access to all settings, routing, mixing, and effects processing in your audio interface, and each interface on the AVB network, if applicable. For more info, see “MOTU AVB Control Web App” on page 13.

The web app is a web application served by the hardware. All you need to run it is a web browser running on a device that has a connection to your audio interface through USB or a shared network.

graph TD
    A["Web app"] --> B["Web app in your browser"]

Figure 4-1: The web app is served from the hardware, and accessed through any web browser on any device connected to the interface.

Web app control can be set up independently of audio connections

The connections in this section, especially the network scenarios, can be set up independently of USB or AVB networking connections you make for audio routing (as shown in the setup diagrams earlier in this chapter). In addition, connections for web app control can be made over standard Ethernet and do not require AVB Ethernet connections. Think of web app control as being separate from audio. Doing so opens up a lot of possibilities for control of your MOTU interface, independent of the connections you make for audio.

Mixing and matching web app control scenarios

The web app connection scenarios shown in the following sections are not exclusive from one another. You can set up as many web app connections as you wish and control your MOTU device from many web app hosts simultaneously.

Launching the web app

Once you've made any of the connections shown in the following sections, launch the web app as explained in “Make hardware and network connections” on page 13.

Web app control over USB or Thunderbolt

If your audio interface is connected a computer with internet access through USB (as shown on page 33), you can access the web app from the computer, or any other device on the network. In this case, make sure you've run the software installer (page 29), which installs drivers that allow your computer to properly communicate with the device.

Web app control through standard Ethernet

Your MOTU interface can also be controlled by the web app running on any device that has a standard Ethernet connection to the interface, either directly with a network cable, through an Ethernet hub, or through WiFi on your local network. The sections on the opposite page show you how to set up each of these connection scenarios.

Ethernet cable

A simple Ethernet cable connection can be used for web app control, even without a USB or Thunderbolt connection to your computer. For example, if you are using your MOTU device as a mixer or audio router, you could control the on-board routing, mixing and effects from the web app through a standard Ethernet connection.

graph TD
    A["Laptop"] -->|Standard Ethernet cable| B["Network port"]
    B -->|Data transfer| A

Figure 4-2: Web app control through a simple Ethernet cable.

Ethernet hub or network (LAN)

In this scenario, both your laptop and your MOTU device are connected to a standard Ethernet hub or home/office network (LAN). You can run the web app on multiple computers simultaneously.

graph TD
    A["Standard Ethernet hub or network (LAN)"] <--> B["Network port"]
    A <--> C["Network port"]
    D["Ethernet cables"] --> A

Figure 4-3: Web app control through a standard Ethernet hub or network (LAN).

WiFi

When using standard WiFi as shown, you can control your MOTU interface from multiple WiFi devices simultaneously.

graph TD
    A["Laptop (optional) Tablet Smart"] --> B["WiFi devices"]
    C["phone"] --> D["WiFi devices"]
    E["Airport or any other WiFi router"] --> F["Network port"]
    G["Ethernet cable"] --> F

Figure 4-4: Web app control through WiFi.

Ethernet network + WiFi

You can, of course, combine the setups shown in Figure 4-3 and Figure 4-4, with WiFi connected to the Ethernet hub or network.

MOTU AVB Switch

The MOTU AVB Switch provides five AVB

Ethernet ports, plus one standard Ethernet port.

Use the AVB ports for MOTU audio interfaces, and use the Ethernet port for WiFi, Ethernet, etc.

MOTU AVB interfaces WiFi router or Ethernet hub/network (Sold separately) MOTU AVB SWITCH

Figure 4-5: Using the Ethernet port on the MOTU AVB Switch.

AUDIO CONNECTIONS

Here are a few things to keep in mind as you are making audio connections to your 24Ai or 24Ao interface.

D-Sub connectors

The 24Ai and 24Ao D-Sub connectors accept standard, female Panasonic/Tascam (AES-59) D-sub cables. Be sure the screws have standard 4-40 threading (not metric threading). For details and pin-outs, see Appendix D, “D-sub Connector Specifications” page (85).

Analog trims

All quarter-inch analog inputs and outputs can be trimmed. This allows them to support a variety of standards, including EBU-R68, SMPTE RP-155, +4dBu, -10dBV, 2vRMS, 1vRMS.

24Ai analog inputs are equipped with high-quality, digitally controlled analog trim that provides a range from -96 to +22 dB in 1dB steps.

24Ao outputs can be trimmed in the DAC at 32 bit resolution. Range is 24 dB.

Trim controls are most easily accessed in the web app. See “Device tab” on page 14. Trim settings can also be accessed in the LCD menu.

Optical

Your MOTU interface provides three banks of ADAT optical (“lightpipe”) connectors. Together, they provide 24 channels of ADAT optical digital I/O at 44.1 or 48 kHz. At the high sample rates (88.2 or 96 kHz), 4-channel SMUX operation provides 12 channels of I/O and supports two modes (item #24 on page 15):

■ Standard — for 2x optical connection to 3rd-party SMUX-compatible hardware products.
■ Type II (Legacy) — for 2x optical connection to legacy MOTU products that are equipped with optical ports and support 2x operation.

The optical ports are disabled when the interface is operating at a 176.4 or 192 kHz.

TOSLink (optical S/PDIF)

Alternately, the optical ports can be configured for stereo TOSLink (optical S/PDIF) in the web app (item #24 on page 15). The optical IN and OUT banks can be configured independently.

SYNCHRONIZATION

If you connect devices digitally to your MOTU device, or if you need to synchronize your MOTU device with an outside time reference such as word clock, you must pay careful attention to the synchronization connections and clock source issues discussed in the next few sections.

Do you need to sync?

If you will be using only your MOTU device's analog inputs or outputs (and none of its digital I/O), and you don't need to resolve your system to external word clock, you don't need to make any sync connections. You can skip this section.

Situations that require synchronization

There are two general cases in which you will need to resolve you MOTU device with other devices:

■ Synchronizing with other digital audio devices so that their digital audio clocks are phase-locked (as shown in Figure 4-6)
■ Resolving your MOTU device to an external clock source
■ Networking multiple MOTU AVB interfaces

Synchronization is critical for clean digital I/O

Synchronization is critical in any audio system, but it is especially important when you are transferring audio between digital audio devices. Your success in using the digital I/O features on your MOTU device depends almost entirely on proper synchronization. The following sections guide you through several recommended scenarios.

Be sure to choose a digital audio clock master

When you transfer digital audio between two devices, their audio clocks must be in phase with one another — or phase-locked. Otherwise, you'll hear clicks, pops, and distortion in the audio — or perhaps no audio at all.

Not phase-locked Phase-locked Device A Device B

Figure 4-6: When transferring audio, two devices must have phase-locked audio clocks to prevent clicks, pops or other artifacts.

There are two ways to achieve phase lock: slave one device to the other, or slave both devices to a third master clock. If you have three or more digital audio devices, you need to slave them all to a single master audio clock.

graph TD
    A["Master"] --> B["Slave"]
    C["Master"] --> D["Slave Slave"]
    E["Master"] --> F["Slave Slave"]
    style A fill:#fff,stroke:#000
    style C fill:#fff,stroke:#000
    style E fill:#fff,stroke:#000
    style B fill:#fff,stroke:#000
    style D fill:#fff,stroke:#000
    style F fill:#fff,stroke:#000

Figure 4-7: To keep the your MOTU interface phased-locked with other digital audio devices connected to it, choose a clock master.

Also remember that audio phase lock can be achieved independently of timecode (location). For example, one device can be the timecode master while another is the audio clock master, but only one device can be the audio clock master. If you set things up with this rule in mind, you'll have trouble-free audio transfers with your MOTU hardware.

SYNCING OPTICAL DEVICES

There are several ways to sync an optical device with the 24Ai or 24Ao:

A. Resolve the other device to the 24Ao
B. Resolve the 24Ai to the other device

C. Resolve both devices to a word clock source

For A, choose Internal (or anything other than Optical) as the clock mode in the Device tab (item #13 on page 14). Then configure the other device to resolve to its optical input.

For B, choose Optical as the clock mode (item #13 on page 14), and configure the other device to resolve to its own internal clock.

For C, choose Word Clock as the clock mode for the 24Ai or 24Ao (item #13 on page 14), and resolve the other device to its word clock input.

SYNCING WORD CLOCK DEVICES

The word clock connectors on your MOTU device allow you to synchronize it with a wide variety of other word clock-equipped devices.

For standard word clock sync, you need to choose an audio clock master (as explained in “Be sure to choose a digital audio clock master” on page 41). In the simplest case, you have two devices and one is the word clock master and the other is the slave as shown below in Figure 4-8 and Figure 4-9.

graph TD
    A["Master"] --> B["Word clock OUT"]
    B --> C["Word clock IN"]
    C --> D["Slave"]
    D --> E["Other device"]

Figure 4-8: Slaving another digital audio device to your MOTU device (a 24Ai in this example) via word clock. For the 24Ai clock source, choose any source besides word clock, as it is not advisable to chain word clock.

Audio clock Master Word clock master device Word clock OUT Word clock IN Slave 24Ai

Figure 4-9: Slaving your MOTU device (a 24Ai in this example) to word clock. For the 24Ai clock source, choose 'Word Clock In'.

Follow system clock / Force 1x clock

When operating the 24Ai or 24Ao at high sample rates (88.2 kHz or higher), the Word Clock Out can either match the interface's operational sample rate or its corresponding 1x sample rate. For example, if the 24Ao is operating at 192kHz, you can choose to generate a word out rate of 48kHz using the Force 1x Clock setting in the Device tab of the MOTU AVB Control web app (item #15 on page 14).

Word clock is not needed for AVB networking

When working with multiple MOTU AVB interfaces on an AVB network, synchronization is handled by AVB, so no word clock connections are necessary. See the next section for details.

SYNCING AN AVB NETWORK

The AVB protocol provides sophisticated and accurate timing, synchronization, and clocking features for AVB device networks of any size as shown on pages 35-36, including:

■ Low latency
■ Network-wide time base
■ Better-than-sample-accurate phase lock across all connected devices
■ Timing accuracy down to the nanosecond

Choosing a master clock

The web app provides an easy way to choose one device as the master clock for your whole MOTU AVB network.

1 Go to the Devices tab (page 14).

2 In the device list (item #1 on page 14), choose the MOTU interface you wish to use as the clock master.

3 Click the Become Clock Master button below the Clock Mode menu.

Now, all other MOTU AVB devices on the network are resolved to this device.

Configuration Quick S Sample Rate: 95000 Clock Mode: Internal Clock Status: Word Clock Out: Force 1x Clock Become Clock Master 24AI will have its clock source changed to Internal. The following devices will be slaved to 24AI: • 112D • 8M Input Settings OK

Figure 4-10: Choosing a clock master.

Alternately, you can go to the clock mode menu for each individual device separately and choose the master clock device by hand. For example, you may be in a situation where at least one MOTU device on the network must remain resolved to its own clock (or another clock source). Just know that in this case, audio cannot be streamed between MOTU AVB devices that don't share the same master clock.

Resolving the master clock device to an external clock source

The MOTU device you've specified as the AVB network clock master can itself be resolved to an external time base such as word clock or optical. Just choose the desired clock source from its Clock Mode menu (in the Device tab). Doing so effectively resolves the entire AVB network to the external clock source.

SYNCING MULTIPLE AVB AUDIO INTERFACES CONNECTED TO A MAC

There are several options for clocking multiple AVB audio devices connected to the Mac:

■ You can resolve them to an external clock source (like word clock, if available).
■ You can create an aggregate device, as usual. The aggregate device setup panel has a check box called Drift Correction, which sample-rate converts devices that are not synchronized.

Part 2

Using your

MOTU interface

CHAPTER 5 Presets

OVERVIEW

Because of its advanced, extensive feature set, your MOTU AVB interface can be used for many different purposes. This chapter discusses common use cases and their corresponding device presets, to help you use the hardware for your needs.

Preset menu

The preset menu (item #7 on page 14) contains a number of presets specifically designed for common use cases. By loading the corresponding preset, your MOTU AVB interface routing tab and mixer will be reconfigured accordingly. You can visit the Routing and Mixing tabs to inspect settings and adjust them as needed.

Audio interface 47

Stand-alone mixer 48

Interface + mixer.... 48

Live recording with monitor mixing 49

Stage I/O.... 49

Studio Input expander.... 50

Studio Output expander.... 50

Optical converter 51

Create your own presets

You can create presets to suit your specific needs. Your MOTU device is highly capable and configurable, allowing it to perform many tasks simultaneously.

Video tutorials

To view several excellent video tutorials for the presets described in this chapter, visit:

www.motu.com/avb

AUDIO INTERFACE

Choose the Audio Interface preset to use your MOTU AVB device as a standard USB audio interface. Hardware inputs and outputs are accessible from your computer, and the mixer and audio networking features are disabled.

graph TD
    A["Laptop"] --> B["Hi-SPEED USB"]
    B --> C["Device with bidirectional arrows"]
    C --> D["Audio Connection to Audio Gear"]

Figure 5-1: Using your MOTU AVB device as an audio interface.

STAND-ALONE MIXER

Choose the Stand-alone mixer preset to use your MOTU AVB device as a mixer. Doing so routes all physical inputs to the mixer with the mixer main out and monitor out going to two hardware output pairs.

To control the mixer (with the AVB Control web app), you have several options. You can connect a computer to your MOTU AVB device using USB, Ethernet, or Wi-Fi, as explained in “Setup for web app control” on page 38. Figure 5-2 below shows the WiFi scenario. Note that you can control the mix from multiple WiFi devices.

Laptop (optional) Tablet Smart WiFi devices phone

graph TD
    A["Main Mix"] --> B["Aux Mix 1"]
    A --> C["Aux Mix 2"]
    B --> D["Audio inputs from stage, etc."]
    C --> D
    D --> E["Ethernet cable"]
    E --> F["Airport or any other WiFi router"]
    F --> G["Wireless"]

Figure 5-2: Using your MOTU AVB device as a stand-alone mixer. This example demonstrates how you can control the mixer from several Wi-Fi devices.

INTERFACE + MIXER

Choose the Interface + Mixer preset to use your MOTU AVB device as both an audio interface and mixer, simultaneously. Doing so routes all physical inputs and outputs to and from the computer, connected through USB. In addition, all MOTU AVB device inputs are routed to the mixer, which mixes them to the Main Mix bus. The Monitor bus is set up as a solo bus.

Specifically for the 24Ai, the internal DSP mixes the analog inputs with eight output channels from the computer. The computer receives analog inputs and the output of the internal mixer.

Specifically for the 24Ao, the internal DSP mixes the ADAT inputs with 8 output channels from the computer. The computer receives ADAT inputs and the output of the internal mixer.

In this scenario, you can control the mixer from the MOTU AVB Control web app running on the computer. You can also run the web app from wireless devices on the same WiFi network as the laptop.

graph TD
    A["Laptop"] --> B["Hi-Speed USB"]
    B --> C["Main Mix"]
    B --> D["Aux Mix 1"]
    B --> E["Aux Mix 2"]
    C --> F["Audio inputs from stage, studio, etc."]
    D --> F
    E --> F

Figure 5-3: Using your MOTU AVB device as an audio interface and mixer, simultaneously.

LIVE RECORDING WITH MONITOR MIXING

Choose the Live recording with monitor mixing preset when you are tracking in the studio. The setup is pretty much the same as for the “Interface + mixer” preset discussed in the previous section, shown in Figure 5-3 on page 48. All physical inputs on the interface are routed to both the computer (for recording) and the Main Mix and Monitor busses in the mixer (for near-zero latency monitoring).

STAGE I/O

Use the Stage I/O preset when you want to route audio inputs from musicians and instruments on stage to another location over Ethernet cabling. This preset routes all inputs and outputs on the MOTU AVB interface to 8-channel AVB network streams in the routing grid, which are then broadcast to any/all other devices on the same AVB Ethernet network.

Single AVB Ethernet "snake"

For example, you could have a single Ethernet cable running from a 24Ai on stage to a 24Ao at the Front of House (FOH) mixer.

graph TD
    A["Audio inputs from musicians on stage"] --> B["Stage area"]
    B --> C["24Ai"]
    C --> D["Ethernet cable"]
    D --> E["24Ao"]
    E --> F["Analog outputs to the mixing console"]
    G["FOH mix position Laptop (optional)"] --> H["Hi-speed Use"]
    H --> I["24Ai"]
    I --> D

Figure 5-4: An example of using the Stage I/O preset. 24Ai analog inputs are routed to network streams. Those streams are carried over the network cable to the 24Ao, which streams them to its analog outputs going going to the mixing console. The computer rig is optional and can be used for backup recording of the performance.

Stage I/O to network

As another example, you could run an Ethernet cable from the stage unit to a MOTU AVB Switch, with a host of other MOTU AVB interfaces and computers on a multi-device network.

graph TD
    A["Audio inputs from musicians on stage"] --> B["24Ai"]
    B --> C["Switch A"]
    C --> D["USB AVB"]
    C --> E["USB AVB"]
    C --> F["USB AVB"]
    C --> G["USB AVB"]
    C --> H["USB AVB"]
    C --> I["USB AVB"]
    C --> J["USB AVB"]
    C --> K["USB AVB"]
    C --> L["USB AVB"]
    C --> M["USB AVB"]
    C --> N["USB AVB"]
    C --> O["USB AVB"]
    C --> P["USB AVB"]
    C --> Q["USB AVB"]
    C --> R["USB AVB"]
    C --> S["USB AVB"]
    C --> T["USB AVB"]
    C --> U["USB AVB"]
    C --> V["USB AVB"]
    C --> W["USB AVB"]
    C --> X["USB AVB"]
    C --> Y["USB AVB"]
    C --> Z["USB AVB"]
    C --> AA["USB AVB"]
    C --> AB["USB AVB"]
    C --> AC["USB AVB"]
    C --> AD["USB AVB"]
    C --> AE["USB AVB"]
    C --> AF["USB AVB"]
    C --> AG["USB AVB"]
    C --> AH["USB AVB"]
    C --> AI["USB AVB"]
    C --> AJ["USB AVB"]
    C --> AK["USB AVB"]
    C --> AL["USB AVB"]
    C --> AM["USB AVB"]
    C --> AN["USB AVB"]
    C --> AO["USB AVB"]
    C --> AP["USB AVB"]
    C --> AQ["USB AVB"]
    C --> AR["USB AVB"]
    C --> AS["USB AVB"]
    C --> AT["USB AVB"]
    C --> AU["USB AVB"]
    C --> AV["USB AVB"]
    C --> AW["USB AVB"]
    C --> AX["USB AVB"]
    C --> AY["USB AVB"]
    C --> AZ["USB AVB"]
    C --> BA["USB AVB"]
    C --> BB["USB AVB"]
    C --> BC["USB AVB"]
    C --> BD["USB AVB"]
    C --> BE["USB AVB"]
    C --> BF["USB AVB"]
    C --> BG["USB AVB"]
    C --> BH["USB AVB"]
    C --> BI["USB AVB"]
    C --> BJ["USB AVB"]
    C --> BK["USB AVB"]
    C --> BL["USB AVB"]
    C --> BM["USB AVB"]
    C --> BN["USB AVB"]
    C --> BO["USB AVB"]
    C --> BP["USB AVB"]
    C --> BQ["USB AVB"]
    C --> BR["USB AVB"]
    C --> BS["USB AVB"]
    C --> BT["USB AVB"]
    C --> BU["USB AVB"]
    C --> BV["USB AVB"]
    C --> BW["USB AVB"]

Figure 5-5: Use the Stage I/O preset to connect audio inputs and outputs to other AVB devices on the rest of the network.

Use the Studio Input Expander preset when you already have a main system set up, but you want to add additional inputs. This preset routes all physical inputs (analog and digital) on the expansion MOTU AVB interface to AVB network streams. You can connect to these expansion streams in AVB Stream Connections section of the Device tab of the main MOTU AVB interface.

Use the Studio Output Expander preset when you already have a main system set up, but you want to add additional outputs. This preset routes AVB network streams to all physical outputs (analog and digital) on the expansion MOTU AVB interface. You must choose which network streams are used in the AVB Stream Connections section of the Device tab of the expansion MOTU AVB interface.

OPTICAL CONVERTER

Choose the Optical converter preset if you would like your MOTU AVB device to serve as a multi-channel analog-to-digital or digital-to-analog converter connected to another device equipped with an ADAT optical port.

For example, if you have a 24Ai, you could connect the 24Ai optical output to the optical input on another device. The 24Ai then serves as a multi-channel expander that adds an additional 24 analog inputs to your setup. The benefit of connecting the 24Ai optically is that you can seamlessly integrate its inputs into the other device, such as the on-board no-latency CueMix mixing environment in MOTU mk3 interfaces.

Similarly, if you have a 24Ao, you could connect the 24Ao optical inputs to the optical outputs on another device. The 24Ao then serves as a multi-channel expander that adds an additional 24 analog outputs to your setup.

graph TD
    A["Audio inputs"] --> B["24Ai interface"]
    B --> C["Optical cable"]
    C --> D["Other optical device"]

Figure 5-6: Use the Optical converter preset to connect additional audio inputs and outputs to another optical device. This example shows 24Ai interface analog inputs being routed to the other optical device, but you could also do the same thing for outputs, even simultaneously.

CHAPTER 6 The Front Panel LCD

OVERVIEW

The front panel LCD displays level meters for all inputs and outputs. The LCD also provides several navigable menus that provide status information and basic hardware settings.

Level meters....53

ID button 53

Menu Navigation 53

Device menu....54

Network menu....54

Settings menu 54

Presets menu....54

Version menu 54

Clock....54

ADAT SMUX Type 54

Stand-alone operation....54

LEVEL METERS

In its default state when the unit is first powered on, the LCD displays level meter activity for all physical audio inputs and outputs on the device.

The meters display from -42dBFS to 0dBFS, as shown by the labels to the left of the LCD display (Figure 6-1).

ID BUTTON

Push ID (Figure 6-1) to immediately view the device's network information, including its IP Address. Push back to return to the meters.

ID BACK SEL 0 -6 -12 -42

Figure 6-1: Buttons on the 24Ai and 24Ao front panel.

MENU NAVIGATION

Push SEL (select) to access the main menu, which provides settings and status information.

Main Menu

Push the up/down arrow buttons to scroll through the menu settings on the left side of the LCD.

Push SEL to enter the selected sub-menu (column of options to the right) or to select the currently highlighted parameter.

Push BACK to go to the parent menu.

To exit the menu entirely, push BACK repeatedly until the menu disappears from the display.

Device menu

The Device menu provides information about the device, such as its name and connection mode (USB or AVB).

Network menu

The Network menu displays the following network-related information:

Setting Explanation

Serial/UID Unique AVB network identifier that can be used for troubleshooting.

IP address The unique network address for the unit.Type this address into your web browser to access the unit's settings in the MOTU AVB Control web app.

AVB Indicates whether AVB networking is currently enabled or disabled. For example, AVB could be disabled because a non-AVB switch is being used. When AVB is disabled, audio streaming over the network is disabled.

Settings menu

The Settings menu provides access to basic hardware settings, such as Clock Mode, Sample Rate, and so on.

Setting What it does

Clock Mode Sets the digital audio clock source for the device.
Sample Rate Sets the sample rate for the device.
Word Clock Thru Mode	Toggles the Word Clock Output between OUT and THRU.
Optical Specifies the SMUX format when operating at 88.2 or 96 kHz. See “ADAT SMUX Type” on page 54.
Configure IP Chooses between DHCP and a manually assigned IP Address.
LCD Contrast Adjusts the contrast of the LCD.
Factory Defaults Restores factory default settings.

Presets menu

The Presets menu lets you recall settings that have been saved as a device preset. Use the web app to create and save presets (item #7 in the "Device tab" on page 14).

Version menu

The Version menu displays firmware version information.

CLOCK

The Clock section of the LCD displays the sample rate at which the unit is currently operating, and the current Clock Mode setting (item #13 in the Devices tab on page 14). The Clock Mode setting can also be found (and changed) in the Settings Menu.

ADAT SMUX TYPE

When your MOTU interface is operating at either 88.2 or 96 kHz, the Settings menu > Optical setting lets you configure ADAT SMUX type. There are two choices:

■ Type I — interoperation with 3rd-party SMUX-compatible hardware products
■ Type II — interoperation with compatible MOTU products

All settings, including mix settings and device settings, are saved in your MOTU interface's memory. They remain in effect even when the interface is not connected to a computer. This allows you to use your MOTU device as a standalone mixer. You can make adjustments to any setting at any time from the web app running on a device that has a network connection to your MOTU interface, as explained in "Setup for web app control" on page 38.

CHAPTER 7 Working with Host Audio Software

OVERVIEW

Your MOTU interface provides multi-channel audio input and output for Core Audio compatible audio applications on the Mac and ASIO or Wave compatible applications on Windows, including MOTU's Digital Performer and AudioDesk, Apple's Logic Pro and GarageBand, and other third-party software applications such as Ableton Live, Avid Pro Tools, Cockos Reaper, Propellerhead Reason and Record, Steinberg Cubase and Nuendo, Cakewalk SONAR, PreSonus Studio One, Bitwig, and others.

AudioDesk is available as a free download for 24Ai and 24Ao owners at motu.com/avb. For complete information about all of AudioDesk's powerful workstation features, refer to the AudioDesk User Guide.pdf included in the AudioDesk application.

Digital Performer, MOTU's state-of-the-art digital audio workstation software, is available separately; for details about upgrading from AudioDesk to Digital Performer, talk to your authorized MOTU dealer or visit motu.com.

Preparation 55

Run the web app.... 55

Choosing the MOTU Audio driver.... 58

Reducing monitoring latency.... 59

Working with on-board mixing and effects.... 61

Synchronization....61

PREPARATION

Install your host audio software first if you haven't already done so, and complete these chapters before proceeding:

■ chapter 3, “Software Installation” (page 29)

■ chapter 4, “Hardware Installation” (page 33)

RUN THE WEB APP

Before you run your host audio software, launch the web app to configure your MOTU hardware.

The web app lets you configure important settings in your audio interface, enable the desired inputs and outputs, and set up audio streams to and from the computer.

Sample rate

Choose the desired sample rate for your interface and your host audio software. Newly recorded audio will have this sample rate.

Clock Mode

This setting is important because it determines the master digital audio clock for your system.

If you do not have any digital audio connections to your MOTU device (you are using the analog inputs and outputs only), and you will not be resolving your host software to word clock or another external clock source, choose Internal.

If you have devices connected to the optical ports, see “Syncing optical devices” on page 41.

If you are slaving your MOTU device and your host software to word clock, follow the directions in "Syncing word clock devices" on page 41.

Enabling and disabling input/output banks

In the web app Device tab (page 15), enable all input and output banks on your MOTU device that you wish to make available to your host audio software. Disable banks you are not using to simplify operation.

Specifying the number of computer channels In the web app Device tab (page 15), in the Computer Setup section, specify the number of computer channels for streaming audio to and from your host audio software. You might want enough channels to cover the following:

■ Physical inputs you want to record on your computer.
■ The physical outputs you want to send audio playback to.
■ Any audio streams going to and from the on-board mixer in your MOTU device
■ Any audio streams going to and from the AVB network, if you have multiple networked MOTU AVB devices

If you aren't sure how many channels you'll need, visit the Routing tab, as explained below.

Making inputs and outputs available to your host software

In the web app, use the Routing tab (page 16) to map inputs and outputs to computer channels, as demonstrated in Figure 7-1 and Figure 7-2.

Configuration presets

The presets menu (item #7 in the Devices tab on page 14) provides many useful presets for various host routing scenarios. These presets are a convenient shortcut for the routing grid setups discussed in the next few sections.

Figure 7-1: An example of routing computer channels (from host audio software) to the analog outputs on a 24Ao.

Naming computer input and output channels Click on any computer input or output name in the routing grid (Figure 7-1) to change its name.

Streaming computer audio to and from the on-board mixer

In Figure 7-1, you'll see "mix" inputs across the top of the grid (Main, Monitor, Aux, etc.) These are output busses from the your interface's on-board mixer. To route one of these mix busses to your host computer software, click the grid at the intersection of the mix column and desired computer channel row. Now, the mix bus output will be routed to the computer via the channel you selected.

Conversely, you can stream audio from the computer into the mixer. Channels coming from the computer are represented across the top of the routing grid as inputs. To route a computer channel to the mixer, click the grid at the intersection of the computer channel column and the desired mix input row. Now, that computer channel will be routed to the mixer input.

Figure 7-2: An example of routing physical inputs on the 24Ai to computer channels (for host audio software).

Working with AVB network streams

Audio channels going to networked AVB interfaces can be streamed to and from your host audio software through the MOTU interface connected directly to the computer. For information about how to set this up, see “Mapping computer channels to network streams” on page 73.

Mirroring computer channels to multiple outputs

Figure 7-1 shows an example of mirroring one stereo audio stream from your host audio software to several outputs. In the example, computer channels 1-2 are being sent to the main outs, plus phones 1-2 and phones 3-4. To route an input to multiple outputs, click multiple boxes in its column, (see computer channels 1-2 in Figure 7-1).

Combining multiple inputs to one output

To merge (mix) any channels in the grid (computer streams or otherwise), route them to mixer inputs and then use the on-board mixer ("Mixing tab" on page 17).

Routing grid tutorials

For further information about using the routing grid, including many useful tips and techniques, visit:

www.motu.com/techsupport/technotes/avbrouting

CHOOSING THE MOTU AUDIO DRIVER

Once you've made the preparations described so far in this chapter, you're ready to run your audio software and enable the MOTU AVB audio driver, which allows your host software to use the the 24Ai or 24Ao as an audio interface.

For Mac OS X audio software

For audio software running under Mac OS X, go to the menu item or preference where you choose the audio device (Core Audio driver) you wish to use, and then select the the 24Ai or 24Ao by name.

For Windows audio software

For audio software running under Windows, go to the menu item or preference where you choose the ASIO driver you wish to use, and then choose MOTU A VB USB ASIO. If your host audio software doesn't support ASIO, choose the MOTU A VB USB AUDIO Wave driver instead.

Device Setup MIDI MIDI Port Setup Transport Record Time Man Time Display Video Player VST Audio System MOTA AVB USD ASD VST Audio System VST Audio System ASIO Driver Reference Description Application is in Background Input Latency: 9.233 ms Output Latency: 9.233 ms ASIO Guard Latency: 10.647 ms HW Sample Rate: 40.000 kHz HW Pull Up/Down: Off Advanced Options Set to Defaults

Figure 7-3: Choosing the MOTU AVB ASIO driver in Cubase.

Where to go in popular audio hosts

Here is the location for this setting in various popular audio software host applications:

Host software Location for choosing the the 24Ai or 24Ao

Digital Performer and AudioDesk	Setup menu > Configure Audio System > Configure Hardware Driver
Pro Tools 9 or later Setup menu > Playback Engine or Current Engine
Logic Pro Preferences > Audio tab > Devices tab > Core Audio tab
Garage Band Garage Band menu > Preferences > Audio/ MIDI > Audio Output/Input menus
Cubase and Nuendo	Device Setup > Devices list > VST Audio System menu
Live Preferences > Audio tab
Reason Preferences > Audio preferences
Reaper Preferences > Audio prefs > Devices

Other audio software

Consult your software's manual for further information.

REDUCING MONITORING LATENCY

Monitoring latency is a slight delay caused by running an input signal through your host audio software and back out. For example, you might hear it when you drive a live guitar input signal through an amp modeling plug-in running in your audio sequencer.

This delay is caused by the amount of time it takes for audio to make the entire round trip through your computer, from when it first enters an input on your MOTU interface, passes through the interface hardware into the computer, through your host audio software, and then back out to an output.

Monitoring through your MOTU interface

If you don't need to process a live input with plug-ins, the easiest way to avoid monitoring latency is to disable your DAW's live monitoring feature and instead use the digital mixer in your MOTU interface to route the input directly to your outputs. For details, see “Mixing tab” on page 17. The mixer in your MOTU interface even provides zero latency effects processing (EQ, compression and reverb), which can be applied to the signal.

Direct hardware playthrough / Direct ASIO monitoring

When managing your live monitor mix through your MOTU interface mixer, remember to disable your DAW's live monitoring features, so that you won't hear record-enabled tracks in your DAW. Also note that your MOTU AVB interface does not support Direct Hardware Playthrough in Digital Performer, or the Direct ASIO Monitoring feature (or similar) offered and other DAWs, which lets you control no-latency hardware monitoring from within the host application. Instead, you can use the MOTU AVB Control web app mixer ("Mixing tab" on page 17) to make these live monitoring connections manually.

If you don't require any effects processing on the input signal (no reverb or compression, for example), all this takes is one click in the routing grid to route the input being recorded to the output you are using for monitoring.

If you are recording a mono input that you'd like to monitor in stereo, or if you need to apply effects to the monitored signal, you can simply route the input to the mixer in your MOTU interface. This is done by opening the Mix In group in the Outputs column along the left side of the grid (Figure 7-2 on page 57), and clicking the tile at the intersection of the input's column and the desired mixer input's row. Once routed to the mixer, use the input channel, reverb bus, and monitor bus in the mixer to apply effects as desired, and perhaps include other channels to the mix, and then assign the monitor bus output in the routing grid to the output you are using for monitoring.

In either case (routing directly in the grid or routing through the mixer), be sure to maintain the input's connection to the computer as well, so the input signal can be recorded in your host software. In other words, you'll want to make sure there are two tiles enabled in the input's column in the grid: one tile for the connection to the computer and another tile for your monitoring output (or a mixer input, if you are using the mixer to apply effects). If you need to route the input signal to other destinations, too, you can certainly do so (you can route the input to multiple destinations).

Monitoring through your host audio software

If you do need to process a live input with host software plug-ins, or if you are playing virtual instruments live through your MOTU audio hardware, you can significantly reduce latency by adjusting the audio buffer setting in your host audio software, as explained in the next section.

It is important to note that monitoring delay has no effect on the recording, or playback, of audio data from disk. The actual recording and playback is extremely precise, it is only the monitoring of your live input signal which may be delayed.

Adjusting your host software audio buffer Buffers are small bundles of audio data. Your interface “speaks” to your computer in buffers, rather than one sample at a time. The size of these buffers determine how much delay you hear when monitoring live inputs through your audio software: larger buffers produce more delay; smaller buffers produce less.

Adjusting buffer size on Mac OS X Under Mac OS X, audio I/O buffer size is handled by the host audio application (not by your MOTU interface's Core Audio driver). Most audio software applications provide an adjustable audio buffer setting that lets you control the amount of delay you'll hear when monitoring live inputs or processing them with software plug-ins. Here are a few examples.

Preferences Central Audio HG Display Audio Mode Automation Myo Advanced Devices General IO Assignments MPS Reset Core Audio: Enabled Output Device: 24A Input Device: 24A I/O Buffer Size: 128 Samples Resulting Latency: 7.3 ms Round-trip (1.6 ms Output) Recording Delay: 0 Samples ✓ 34-Bit Recording ✓ Software Monitoring ✓ Input monitoring only for focused track, and record-enabled tracks ■ Independent monitoring level for record-enabled channel strips Processing Threads: Automatic Process Buffer Range: Medium ReWire Behavior: Off Maximum Scrub Speed: Normal Scrub Response: Normal Apply Changes

Figure 7-4: In Logic Pro, go to the Audio Driver preferences to access the Buffer Size option shown above.

Configure Hardware Driver CoreAudio Built-in Output Display Audio 24AI Master Device: 24AI Sample Rate: 48000 Clock Modes: 24AI Buffer Size: 256 Host Buffer Multiplier: 1 Work Priority: High Cancel OK

Figure 7-5: In Digital Performer and AudioDesk, choose Setup menu> Configure Audio System> Configure Hardware Driver to open the dialog shown above and access the Buffer Size setting. Refer to your Digital Performer or AudioDesk manual for information about the Host Buffer Multiplier setting.

Device Setup VST Audio System 24AI ASIO Driver Release Driver when Application is in Background Input Latency: 6.780 ms Output Latency: 6.621 ms 256 Samples - Audio Buffer Size Advanced Options Set to Defaults High - Audio Priority 2 Seconds - Disk Preload Lower Latency Multi Processing Adjust For Record Latency 0 Samples - Record Shift Help Reset Apply Cancel OK

Figure 7-6: In Cubase or Nuendo, choose Devices menu > Device Setup. Select your interface (24Ai or 24Ao), then click the Control Panel button to access the window above and the Buffer Size setting.

Adjusting buffer size on Windows To adjust buffer size on Windows, visit the MOTU AVB USB Control Panel. See “MOTU AVB USB Control Panel” on page 30.

Lower latency versus higher CPU overhead

Buffer size has a large impact on the following:

■ Monitoring latency
■ The load on your computer's CPU
■ Responsiveness of transport controls and effect knobs in AudioDesk, Digital Performer or other audio software.
■ Real-time virtual instrument latency.

The buffer setting presents you with a trade-off between the processing power of your computer and the delay of live audio as it is being patched through your software. If you reduce the size, you reduce monitoring latency, but significantly increase the overall processing load on your computer, leaving less CPU bandwidth for things like real-time effects processing. On the other hand, if you increase the buffer size, you reduce the load on your computer, freeing up bandwidth for effects, mixing and other real-time operations.

Audio Performance CPU Playback Record

Figure 7-7: When adjusting the buffer size to reduce monitoring latency, watch the 'processor' meter in Digital Performer or AudioDesk's Performance Monitor. If you hear distortion, or if the Performance meter is peaking, try raising the buffer size.

If you are at a point in your recording project where you are not currently working with live, patched-thru material (e.g. you're not recording vocals), or if you have a way of externally processing inputs, choose a higher buffer size. Depending on your computer's CPU speed, you might find that settings in the middle work best (256 to 1024).

Transport responsiveness

Buffer size also impacts how quickly your audio software will respond when you begin playback, although not by amounts that are very noticeable. Lowering the buffer size will make your software respond faster; raising the buffer size will make it a little bit slower.

Effects processing and automated mixing

Reducing latency with the buffer size setting has another benefit: it lets you route live inputs through the real-time effects processing and mix automation of your audio software.

WORKING WITH ON-BOARD MIXING AND EFFECTS

Your MOTU interface provides powerful mixing, EQ, compression and reverb, which can operate hand-in-hand with your host's mixing environment. For example, your MOTU interface can serve as a monitor mixer, routing channels to musicians, or it can serve as an integrated extension of your host's mixing environment. You can even save a particular mixing configuration as a preset for future recall. For details, see “Mixing tab” on page 17.

SYNCHRONIZATION

You may encounter situations in which you need to synchronize your audio software and your MOTU interface to other components of your system. For details, see “Synchronization” on page 40.

CHAPTER 8 Mixer Effects

OVERVIEW

This chapter provides further information about the effects processors available in the DSP mixer in your MOTU AVB interface. For basic mixer operation, see:

Mixing tab....17

Aux Mixing tab 18

Mixer input channel strips.... 19

Main Mix and Monitor channel strips.... 20

Aux bus channel strips.... 21

Group and Reverb channel strips.... 22

Powerful DSP-driven mixing and effects

The mixer is driven by a powerful DSP that delivers 32-bit floating point precision and plenty of processing bandwidth for no-latency effects, including parametric EQ, dynamics, and reverb. Effects can be applied when operating as an audio interface or as a stand-alone mixer without a computer. Input signals to the computer can be recorded wet and/or dry, or recorded dry while a real-time wet monitor mix is sent to musicians. Effects include:

High Pass Filter 63

A conventional high pass filter

Gate 64

A standard gate with threshold/attack/release controls

Four-band parametric EQ.... 64

Multi-band parametric EQ modeled after British analog consoles

Compressor.... 65

A standard compressor with threshold/ratio/attack/release/gain controls

Leveler 66

The Leveler™, an accurate model of the legendary LA-2A optical compressor, which provides vintage, musical automatic gain control

Reverb 67

Classic reverb with tail lengths up to 60 seconds

Advantages over host-based mixing and processing

The hardware mixer in your MOTU AVB interface provides several major advantages over mixing and processing in your host audio software:

• No buffer latency. The DSP-mixer provides the same near-zero latency throughput performance as a conventional digital mixer. Effects processing doesn't impact your computer's CPU.
  ■ DSP mixing and routing can be maintained independently of individual software applications or projects.
  ■ DSP-driven mixing can function without the computer, allowing your MOTU AVB device to operate as a portable, stand-alone mixer with effects.
  Effects are disabled when operating at 4x sample rates (176.4 or 192 kHz).

HIGH PASS FILTER

All input channel strips provide a 12 dB per octave high pass filter. High Pass filters are often used to remove unwanted mic rumble, for example.

Figure 8-1: The High Pass Filter.

GATE

All input channel strips provide a Gate module.

Gate Gate Attack Thresh Release

Figure 8-2: The Gate module.

The gate silences the signal when the input signal's level drops below the Threshold.

The rate at which the gate responds, (opens to let signal through) is determined by the Attack parameter. With a short Attack time, the gate will open as soon as the signal crosses the Threshold; with longer Attack times, the gate will gradually open, much like a fade-in.

When the input level falls back below the Threshold, the time it takes for the gate to close (how quickly the signal is attenuated), is determined by the Release parameter. Short Release times will close the gate quickly, abruptly attenuating your signal, versus longer release times, which will gradually attenuate your signal, like a natural fade-out.

FOUR-BAND PARAMETRIC EQ

All mixer channel strips, (except for the Monitor bus), provide modeled, four-band parametric EQ.

Vintage EQ

Inspired by legendary British large console EQs, the EQ section (Figure 8-3) models the sound of the most sought-after classic equalizers. Four bands of center frequency parametric EQ filtering are provided, each with a bandwidth control. The High and Low bands include a shelf filtering option. With 32-bit floating point precision, the vintage EQ has been carefully crafted and meticulously engineered to produce musical results in a wide variety of applications.

Enabling EQ

Each band has an enable/disable button (Figure 8-3), allowing you to enable as few or as many bands as needed for the channel strip.

EQ High Gain Freq Shelf Mid Gain Freq Bandwidth Mid Gain Freq Bandwidth Low Gain Freq Shelf Enable/disable Disabled band

Figure 8-3: The Four-band parametric EQ module.

EQ filter controls

The EQ filters have three controls:

Control unit range

Gain dB -20.00 to +20.00

Frequency Hertz 20 to 20,000

Bandwidth Octaves 0.01 to 3.00

Double-click a knob to return to its default position.

EQ filter characteristics

EQ is one of the most widely used processing tools and can be applied to many different situations, from minor corrective tasks to creative tone sculpting. The four-band EQ has been designed to

be flexible enough to cover a broad range of applications. By adjusting Gain and Bandwidth together, you can emulate the smooth and musical character of classic analog EQ circuits, in which the Gain/Bandwidth dependency was dictated by the actual circuit design and electrical components used.

Low and high shelf filters

The Low and High bands offer a shelf option that is similar to those found in most conventional parametric EQs.

COMPRESSOR

All mixer input channel strips provide a compressor module.

Compressor Comp Thresh Ratio RMS Gain Attack Release Level Gain Reduction

Figure 8-4: The Compressor module.

The Compressor (Figure 8-4) lowers the level of the input when amplitude of the signal is above the Threshold. The amount of attenuation is determined by the Ratio and the input level. For example, if the input is 6 dB above the Threshold and the Ratio is 3:1, the compressor will attenuate the signal to 2 dB above the Threshold. When the input level goes above the threshold, the attenuation is added gradually to reduce distortion. The rate at which the attenuation is added is determined by the Attack parameter. Likewise, when the input level falls below the Threshold, the attenuation is removed gradually. The rate at which the attenuation is removed is determined by the Release parameter. Long Release times may cause the audio to drop out briefly when a soft passage follows a loud passage. Short Release times may cause the attenuation to “pump”, a term used to describe the sound of the compressor when the average input level quickly fluctuates above and below the Threshold. These types of issues can be addressed by adjusting the compressor’s parameters, or applying the Leveler instead. Gain adjusts the overall output level of the compressor, post processing. The Level meter (Figure 8-4) shows the level of the input signal entering the compressor. It shows either the Peak envelope or the RMS level, if enabled.

Gain reduction meter

The Gain reduction meter (Figure 8-4) displays the current amount of attenuation applied by the compressor, before the makeup gain stage.

RMS mode

By default, the compressor operates in Peak mode, which uses signal peaks to determine the input level. In RMS mode, the compressor measures the input signal's loudness, using the root-mean-square computational method. When RMS is disabled, RMS mode will let brief peaks through because the detector sidechain is only looking at the average signal level. By contrast, peak mode will catch those brief peaks. Peak mode is generally used for drums, percussion and other source material with strong transients, while RMS mode is mostly used for everything else.

The level meter shows either the peak level or the RMS level, depending on the mode.

LEVELER

The Leveler ^™ (Figure 8-5) provides an accurate model of the legendary Teletronix ^™ LA-2A ^® optical compressor, known for its unique and highly sought-after Automatic Gain Control (AGC) characteristics.

Figure 8-5: The Leveler module.

The Leveler is available on the Main Mix bus and all Group busses, including the Reverb bus.

A model of an optical compressor

An optical leveling amplifier works by shining a light on a photoresistor. The intensity of the light source is proportional to the audio signal, and the resistance of the photoresistor is in turn inversely proportional to the intensity of the light. Photoresistors respond quite quickly to increases in light intensity, yet return to their dark resistance very slowly. Thus, incorporation of the photoresistor into an attenuator followed by an amplifier which provides make-up gain produces a signal which maintains a constant overall loudness.

Automatic gain control using light

The AGC circuit of the LA-2A uses a vintage optocoupler known by its model number T4. The T4 contains an electroluminescent-panel (ELP) and photoresistor mounted so that the emission of the panel modulates the resistance. An ELP consists of a thin layer of phosphorescent material sandwiched between two insulated electrodes to form a capacitor. Making one of the electrodes transparent allows the light to escape. These devices are essentially glow-in-the-dark paint on a piece of foil covered by metalized glass or plastic, and are the same devices used in low-power night lights. Unfortunately, these devices need high voltages to operate, and are best driven by tube circuits which can supply voltage swings of several hundred volts.

Response characteristics

Once the light has faded away, the photoresistor then decays back to its dark state. The shape of the decay curve varies depending on how bright the light was, and how long the light lasted. A general rule of thumb is that the louder the program, the slower the release. Typically, the release can take up to and over one minute. One thing to keep in mind when using these types of devices is that the typical concepts of compression ratio, attack, release, and threshold do not apply. The light intensity is determined by the highly non-linear interactions of the input signal, AGC circuit, and ELP, and thus exhibit a strong program dependence that is impossible to describe without the mind-numbing mathematics of statistical mechanics. The actual results, however, can be almost mystical: even when you feed the same material (a loop perhaps) through the Leveler twice, you'll often see a new response the second time through a loop, complete with unique attack times, release times and compression ratios. Furthermore, two different input signals with the same RMS levels may be leveled in a drastically different manner.

It is precisely this self-adjusting behavior that makes optical compressors the tool of choice for smoothing out vocals, bass guitar and full-program mixes without destroying perceived dynamics.

Enabling or disabling the Leveler

The Leveler models the LA-2A so closely, it also models the time it takes for an actual LA-2A to "warm up" after it is turned on. Therefore, when you enable the Leveler, give it a moment to "settle" before you begin processing signals with it.

Gain Reduction

Gain Reduction (Figure 8-5) sets the strength of the signal sent to the AGC model.

Makeup Gain

Makeup gain (Figure 8-5) amplifies the output signal to make up for gain reduction.

Limit button

The Limit button (Figure 8-5) models the original LA-2A Limit/Compress mode switch. The effect is very subtle, with the Limit option behaving only slightly more like a limiter than a compressor. The switch increases the level of the input to the AGC model and runs the attenuator at a slightly lower level. The Leveler then responds more strongly to transients, but otherwise still behaves like a leveling amplifier.

REVERB

Use the enable/disable button (Figure 8-6) to turn the reverb processor on or off. Since reverb uses considerable DSP resources, it is best to leave it off when you are not using it.

Reverb Reverb Time Mod Predelay Spread High Ratio Mid Ratio

Figure 8-6: The Reverb processor.

Routing inputs and groups to the reverb processor

The reverb processor is a single, independent unit that provides stereo reverb. You can route any input channel or Group bus to the Reverb processor with the Reverb send on its channel strip. All incoming signals to the reverb processor are merged and processed together. The resulting stereo output from the reverb can then be merged into the Main Mix bus with the Main send on the Reverb channel strip (item #6 on page 22).

Reverb Time

Reverb time (Figure 8-6) determines the length of decay, or tail, of the reverb. The knob's range is from 100 milliseconds to 60 seconds.

Predelay

Predelay is the amount of time before the acoustic energy from the source returns to the listener, after reflecting off the surfaces of the listening space. The very first reflections helps you perceive information about the listening space, (size, distance, surface type, etc.). In large rooms, it takes a while (on the order of milliseconds) before the first reflections return to the listener. Predelay is useful for adding clarity, as it delays these reflections, before the onset of full reverberation. For example, with pre-delay added to vocals, the reflections won't start until after the initial sound of a word has been sung.

Spread

Spread controls stereo imaging. A position of 12 o'clock produces essentially a mono image. Turning the control all the way to the left completely swaps the stereo image.

High and Mid frequency bands

The High and Mid frequency bands let you independently control the reverb time for separate frequency bands, relative to the low frequency reverb time. The High setting represents the bottom frequency of the High band; the Mid

setting represents the bottom frequency of the Mid band. The Ratio determines the length for each band specified in a percentage of the low frequency reverb time.

DSP USAGE

The DSP Usage meter (item #26 on page 19) shows how much of the available DSP processing power is currently being used by the mixer for the mix and for effects processing. If there aren't enough DSP resources for all effects to be enabled on a channel, effects are disabled for that channel and all subsequent channels.

Unlike other effects, HPF and EQ on a stereo channel requires approximately twice the DSP resources as on a mono channel.

CHAPTER 9 Networking

OVERVIEW

The Audio Video Bridging (AVB) network port on your MOTU interface opens up a world of possibilities for creating expanded, customized audio network systems.

About AVB 69

MOTU's AVB implementation 70

Networking examples....70

A quick guide to networking 72

Setting up a MOTU AVB interface for networking.... 73

Mapping audio to network streams 73

Mapping computer channels to network streams ... 73

Bridging to Ethernet 74

The MOTU AVB Switch 74

ABOUT AVB

Audio Video Bridging (AVB) is an extension of the Ethernet standard developed by the IEEE (802.1 standards committee) specifically to add high-performance audio and video networking. AVB brings together the worlds of networking technology and high-end audio. Here is a brief summary of some of the immediate benefits of AVB for you, as a MOTU AVB interface user:

■ An open industry standard — AVB has been developed by the IEEE as an international standard specification. It is not proprietary or controlled by one company.
■ High channel counts — AVB provides hundreds of network channels.
■ Extremely low latency — AVB guarantees low-latency, real-time performance.
- Guaranteed Quality of Service (QoS) — AVB's Stream Reservation Protocol provides Guaranteed Quality of Service for each and every audio stream. If the network cannot continuously maintain every

bit of every sample in the audio stream, it will not allow you to make the network connection in the first place. AVB streams are prioritized over other network traffic to ensure high performance.

■ Network-wide clocking and sync — AVB devices all clock together over your network for better-than-sample-accurate phase lock across all connected devices. Timing accuracy is down to the nanosecond.
■True plug-and-play operation — AVB has been designed from the ground up to provide automatic device discovery, enumeration, and connection management. Just plug your MOTU AVB interfaces into a standard AVB switch and go. If you wish to make stream connections and have the ability to select media clock, you must use the web app, or some other AVB controller. You don't need an IT professional to configure the network. AVB is a self-managing network protocol.
■ Bridging to standard Ethernet — AVB cooperates with standard Ethernet networks, for connecting traditional Ethernet devices like wireless routers, switches, or any other non-AVB-aware device.
■ Support for existing network infrastructure — Replace your existing switches with standard AVB-compatible switches, and your CAT-5e or CAT-6 wired infrastructure now supports AVB.
■Long cable runs — a single AVB network connection can run up to 100 meters with a standard copper wire CAT-5e or CAT-6 cable. Fiber-optic cable runs can be much longer. With multiple switches, you can create a network that covers very large distances, if necessary. You can use up to seven “hops” (switch-to-switch connections).

■ AVB is already shipping on current Macs — Apple supports AVB on all current shipping Macs, and the 24Ai and 24Ao can operate as a standard AVB audio interface when connected to your Mac's AVB-equipped Ethernet port.

MOTU'S AVB IMPLEMENTATION

MOTU engineering has faithfully implemented the IEEE 802.1 AVB standard for the MOTU AVB products. This means that MOTU devices are fully interoperable with any 3rd party AVB-compatible device. In addition, MOTU has fine-tuned AVB operation among MOTU AVB devices for optimum performance, within the AVB specification. Here is a brief summary of advantages you will enjoy when using MOTU AVB devices together in a network:

■ 256 channels of host I/O — MOTU AVB interfaces equipped with Thunderbolt (the 1248, 8M, 16A and 112D) support 256 simultaneous channels of audio I/O (128 in, 128 out) to and from the entire network.
■Support for multiple computer hosts — All computers and all network devices run in sync with each other, resolved to the network's master clock.
■ Gigabit Ethernet — The MOTU AVB Switch deliver 1 Gbit Ethernet performance, which provides substantially higher bandwidth than 100 Mbit Ethernet. This allows you to have many more devices on the AVB network.
- Over 500 channels of network audio — MOTU's AVB network can stream over 500 channels of audio throughout the network. Depending on the model, some MOTU AVB devices can broadcast sixteen 8-channel network streams and simultaneously listen to sixteen 8-channel network streams.

■ Exceptionally low network latency — Standard AVB network latency is 2 ms. MOTU AVB network latency is an astonishing 0.6 ms, even over seven “hops” (switches) and hundreds of meters of cable. By comparison, other commercially available, proprietary audio network protocols have variable (unpredictable) network latency in the range of 2-5 ms.

■ Star configuration — MOTU AVB supports a star network configuration, which is much more flexible than daisy-chain scenarios, which depends on all devices in the chain.
■ Web interface — MOTU AVB devices can be controlled from the MOTU AVB Control web app, which runs within any web browser on any networked laptop, tablet, or smart phone. Although the web app shares the network with AVB, AVB audio streams are never compromised because AVB streams over the network traffic.
■ Bridging to standard Ethernet — the MOTU AVB Switch provides an extra standard Ethernet port for bridging to your local Ethernet network, Wi-Fi, etc. for command and control, internet access, and other standard network traffic. All ports allow connection to standard (non-AVB) network devices, however, the “Ethernet” port is suggested because it does not support AVB.

NETWORKING EXAMPLES

Networking comes into play as soon as you hook up a second MOTU interface to your first one, as explained in “Setup for two interfaces” on page 34, to add more I/O to your studio. Here are just a few examples of what is possible.

Personal studio expansion

Let's say you have a 24Ai mounted in a rack next to your computer. You could add an 8M interface and position it across the room, near your drum kit, for placing up to 8 mics on the drums. All the mic cabling is kept near the drums, and you have one simple, clean network cable running back to your

computer system. Despite the distance, the two interfaces operate as a seamless system, controlled from your computer or iPad.

Studio installation

A studio installation of three to five interfaces can be handled with a single MOTU AVB Switch. See "Setup for three to five interfaces" on page 35.

Networking is ideal for studio installation because you can position interfaces at strategic locations. Running cables becomes much simpler and more cost effective. Not only does a setup like this give you access to all I/O from your computer, even multiple computers, you can also route audio from any input to any output across devices with near zero latency. You can also route audio from one computer to another with very low latency. As a simple example, you could deploy several interfaces in a studio as follows:

Interface Location Purpose

24Ao Control room Multi-channel output in control room for main monitors, secondary monitors, surround, etc.
1248 Iso booth Local mic and instrument I/O in the iso booth.
1248 Studio room General purpose I/O for studio A
8M Studio room More mic inputs, or additional mic inputs for drum kit
8M Studio room drum kit	8 more mics on the drum kit

24Ai Machine room Analog inputs for hardware synths, outboard returns, etc.

Large studio facility

In a larger studio facility, you could build audio network neighborhoods similar to the studio installation described earlier in multiple rooms, even multiple floors, with multiple computers and WiFi control from anywhere in the facility. All computers and devices can see each other and you can stream audio anywhere on the network with near-zero latency, as if any two devices were connected directly to each other.

Concert systems

Concert systems must be flexible so they can adapt to each new venue while on tour. Because of its modular nature, AVB networking allows you to design systems that are scalable and easy to adapt to each venue. You can easily bring devices on and offline, rerouting audio stems as needed.

Because MOTU AVB networking employs a star configuration, instead of daisy-chaining, you can set up backup computer playback systems on a shared network. For example, in a concert setting, if one computer system goes down, the backup system can be brought on line instantly through the same network infrastructure.

Traditionally, live performance setups often have separate domains for front of house mixing, monitor mixing, computer backline, and other systems. With MOTU AVB networking, these systems can be unified on the same network, opening up many possibilities for shared resources and mixing/routing responsibilities, especially from multiple sources (laptops, iPads, tablets, etc.) MOTU AVB networking handles audio in convenient 8-channel stems, making large-scale network management more manageable. MOTU AVB's very low latency makes it particularly suitable for line arrays and sound reinforcement.

Large-scale venues

With long cable runs and industry standard networking infrastructure, MOTU AVB systems are well-suited for large-scale commercial installations such as arenas, stadiums, theme parks, clubs, casinos, houses of worship, broadcast facilities, schools, universities, and so on. Audio streams can travel long distances with sub-

millisecond latency through as many as seven switches. Audio can be distributed from a centralized location to anywhere in the venue.

A QUICK GUIDE TO NETWORKING

MOTU AVB networking has been designed to be powerful, yet straightforward to set up and use. Here are a few things that are useful to know.

Networking basics

■ Before proceeding below, review the networking connection diagrams on pages 34-36.
■ When making network connections, use shielded CAT-5e or CAT-6 cables (a higher grade cable).
■Network cable lengths can be long: 100 meters with standard copper wire cables; much longer with fiber-optic network cables.

Working with AVB switches

■ Networks of three or more interfaces require an AVB-compatible switch. You can use any standard AVB switch on the market. MOTU offers the five-port MOTU AVB Switch™ (sold separately).

A non-AVB compatible switch will not work.
■ Connect MOTU AVB interfaces to any AVB Switch using their NETWORK ports.
■ On the MOTU AVB Switch, connect MOTU interfaces to the five AVB NETWORK ports (not the Ethernet port). Connect the Ethernet port to a WiFi router, your Local Area Network (LAN) or your computer (for running web app only).

MOTU AVB interfaces or other AVB switches WiFi router, Ethernet hub/network, or computer (Sold separately) MOTU AVB SWITCH

■ Expand the network by adding more switches. Make a single connection from one switch to the other. On MOTU AVB Switches, use their AVB NETWORK ports, NOT the Ethernet port.
- You can daisy-chain switches in serial fashion, but don't create loops. For example, in the network below, do not make any additional connections between any two switches.

graph TD
    A["Source Node A"] --> B["Node B"]
    A --> D["Node D"]
    A --> F["Node F"]
    B --> C["Node C"]
    D --> E["Node E"]
    F --> G["Node G"]
    C --> E
    E --> G
    style A fill:#f9f,stroke:#333
    style B fill:#ccf,stroke:#333
    style C fill:#cfc,stroke:#333
    style D fill:#fcc,stroke:#333
    style E fill:#cff,stroke:#333
    style F fill:#ffc,stroke:#333
    style G fill:#cfc,stroke:#333

■ AVB audio can't pass through more than seven switches. However, you can daisy-chain more than seven switches and route audio freely among them. You just won't be able to create point-to-point connects that span more than seven switches.

Working with computers on a network

■ Computers are not required for network operation, as you can control the network from iPads, tablets and smart phones.

■ To add computers to the network, connect them to any interface using Thunderbolt (which offers the highest possible channel counts). If Thunderbolt is not available, use USB.
- A computer can be connected to the network through its Ethernet port, but only for the purposes of running the web app on the computer for command and control over the network. (In this scenario, you won't be able to stream audio to/from the network from the computer.)
■ All computers and interfaces on the network have full access to each other.
■ MOTU employs a 1 Gbit AVB implementation in the MOTU AVB Switch. The switch allows routing of many audio channels on the network.

SETTING UP A MOTU AVB INTERFACE FOR NETWORKING

Depending on the model, MOTU AVB interfaces have the ability to broadcast up to sixteen 8-channel streams to the rest of the network. Conversely, it can “listen” to as many as sixteen 8-channel streams from anywhere else in the network. The specific number of streams supported depends on the model.

For each device on the network, set it up for network operation as follows:

1 In the MOTU AVB Control web app, choose the device (item #1 on page 14).
2 Go to the Device tab (item #5 on page 14), go to the AVB Stream Setup section (item #25 on page 15), and type in the number of 8-channel input and output streams you want for that device.
3 Go to the AVB Stream Connections section (item #9 on page 15), and choose the network stream you want the device to listen to for each bank.

4 Use the Routing tab to map specific I/O channels within each MOTU AVB interface to its network input and output streams, as explained in the next section.

MAPPING AUDIO TO NETWORK STREAMS

Once you've configured a device's AVB streams, as explained above, use the Routing tab (page 16) to map audio channels to network input and output streams.

Input streams (coming from the rest of the network) are listed across the top of the routing grid. Expand the stream and click on the grid to map incoming network channels to local destinations, including physical outputs on the device, computer channels (to a connected computer), or mixer channels.

Output streams being broadcast to the rest of the network are listed in rows along the left side of the grid. Expand each stream bank and map individual network output channels to local sources, such as physical inputs on the interface, channels coming from the computer, or channels coming from the device's mixer.

MAPPING COMPUTER CHANNELS TO NETWORK STREAMS

If a host computer is connected to an interface (through USB), mapping network input and output streams is accomplished as described in the previous two sections. Simply enable AVB streams as desired, and map them to computer channels in the Routing grid.

If, while mapping, you run out of computer channels, enable more in the Computer Setup section of the Device tab (item #21 on page 15). If the computer is connected with Thunderbolt, you can enable a maximum of 128 channels in and out. If the computer is connected with USB, performance will vary, depending on the sample rate and other factors.

BRIDGING TO ETHERNET

The Ethernet port on the MOTU AVB Switch allows you to connect standard network devices, such as:

■A WiFi router
■ An Ethernet hub or switch connected to a local home, studio, or office network
■ Any other standard networking device

THE MOTU AVB SWITCH

The heart of a MOTU AVB network is the MOTU AVB Switch (sold separately). For a brief overview of the switch and its features, visit:

www.motu.com/products/avb/avb-switch.

Part 3

Appendices

APPENDIX A Troubleshooting

Some or all of my MOTU interface inputs and outputs are not available in my host audio software.

Make sure that the inputs and outputs are enabled in the Device tab (“Device tab” on page 14) and routed to and from the computer in the Routing tab (“Routing tab” on page 16). For details, see “Making inputs and outputs available to your host software” on page 56.

I have absolutely no audio input or output happening to or from my interface. Why?

Make sure that the unit has a stable sample rate (the sample rate will flash if the clock hasn't settled yet). Try setting the unit's clock source to Internal if you can't sync to any external clock sources. Check that audio is working with Internal sync, and if so, then work on establishing a stable external clock.

I can't hear computer audio output through my MOTU AVB interface.

In the Sound panel of System Preferences, your MOTU AVB interface should be selected as the output device. Almost all applications will use just the first two output channels, so make sure that From Computer 1 and From Computer 2 are routed to the physical outputs that you are listening to in the Routing tab (e.g. Phones 1-2 or Analog 1-2).

How do I monitor live inputs?

Please refer to the documentation for the audio application that you are using. If your application does not support input monitoring, you will need to use the mixer in your MOTU interface. Please see “Monitoring through your MOTU interface” on page 59.

How do I control monitoring latency?

See "Reducing monitoring latency" on page 59.

The Routing tab (page 16) doesn't display some of the inputs or outputs on my interface.

The Routing tab only displays input and output banks that are enabled in the Device tab (page 14), so be sure any banks you wish to work with are enabled there. However, to conserve DSP resources and help consolidate screen-space in the other tabs, it is efficient practice to disable unused input or output banks (optical banks, for example, when only working with analog banks).

I'm getting a "Could not enable this effect because DSP is overloaded" error. What should I do?

Disable other effects or reduce the number of mixer inputs to conserve DSP resources. If there are audio input and output banks on your interface that you are not using (such as the optical banks), disable them in the Device tab (page 14).

I accidentally deleted my factory presets. How do I restore them?

In the Device tab (page 14), click the Restore Factory Presets button to restore all factory presets.

How do I factory reset my device?

Push the SELECT knob/button to enter the main menu. Navigate to Settings > Factory Default and push the SELECT knob/button twice to reset.

I can't authenticate AudioDesk.

When authenticating AudioDesk, the OK button does not become active until you have entered in your name and a valid keycode. Your name must contain at least three characters, and you must enter the keycode exactly as it appears (on the jacket of your AudioDesk installer disc). If you continue to have difficulties, try repairing Mac OS X disk permissions using Disk Utility.

I hear clicks and pops under word clock sync.

Many problems result from incorrect word clocking. It is essential that all digital devices in the system be word locked. Consult “Synchronization” on page 40 for detailed information on how to word clock your gear. Whenever there is any unexpected noise or distortion, suspect incorrect word lock.

Clicks and pops due to hard drive problems...

If you have checked your clock settings and you are still getting clicks and pops in your audio, you may have a drive related problem. Set your Clock Source to Internal and try recording just using the analog inputs and outputs on your MOTU interface. If you encounter the same artifacts you may want try using another drive in your computer. Clicks and pops can also occur when the drive is severely fragmented or there are other drive-related issues.

Connecting or powering gear during operation...

It is not recommended that you connect/disconnect, or power on/off devices connected to your MOTU interface while recording or playing back audio. Doing so may cause a brief glitch in the audio.

CUSTOMER SUPPORT

We are happy to provide complimentary customer support to our registered users. If you haven't already done so, please take a moment to register online at MOTU.com, or fill out and mail the included registration card. Doing so entitles you to technical support and notices about new products and software updates.

TECHNICAL SUPPORT

If you are unable, with your dealer's help, to solve problems you encounter with your MOTU device, you may contact our technical support department in one of the following ways:

■ Tech support hotline: [phone] (Monday through Friday, 9 a.m. to 6 p.m. EST)
■ Online support: www.motu.com/support

Please provide the following information to help us solve your problem as quickly as possible:

■ The serial number of your MOTU device. This is printed on a label placed on the bottom of the rack unit. You must be able to supply this number to receive technical support.
■ A brief explanation of the problem, including the exact sequence of actions which cause it, and the contents of any error messages which appear on the screen.
■ The pages in the manual that refer to the features or operation of your MOTU AVB Device or AudioDesk with which you are having trouble.
- The version of your computer's operating system.

We're not able to solve every problem immediately, but a quick call to us may yield a suggestion for a problem which you might otherwise spend hours trying to track down.

If you have features or ideas you would like to see implemented, we'd like to hear from you. Please write to the Development Team, MOTU Inc., 1280 Massachusetts Avenue, Cambridge, MA 02138, or use our online suggestion box at www.motu.com/suggestions.

APPENDIX B Audio Specifications

24Ao

Line Out

Connector Type Panasonic/Tascam format “DB-25” D-Sub AES-59 pin-outs, 4-40 retaining screw

Phoenix screw block Pin-outs as indicated by connector labeling

Output Impedance 100 ohm Per leg

Dynamic Range 123 dB A-weighted

THD+N -110 dB (0.0003%) -1 dBFS, Unweighted, 1 kHz

Frequency Response +0, -0.1 dB, 20 Hz/20 kHz Ref. 1 kHz

Max Level Out +20 dBu

Trim Range 24 dB -4 dBu to +20 dBu in 1 dB steps

Word Clock In/Out/Thru

Specification	AES-11 2009 Annex B
Connector Type BNC
Termination	75 ohm (in/out)	THRU is unterminated
Lock Range	44.1 kHz / 48kHz, +- 0.5%	x1/x2/x4
Input	1 vpp to 3 v p-p (with termination)	AC coupled
Output	5.0 vpp, (2.5 v p-p terminated)	DC coupled
Jitter	complies with AES3-4-2009	< 0.025 UI

Power Supply

Connector Type IEC 3-conductor receptacle	For AC mains connection
Configuration	Internal, Universal
Power Input	100 V to 240 V, 50 Hz or 60 Hz
Power Usage	35 watts

24Ai

Line In

Connector Type Panasonic/Tascam format “DB-25” D-Sub AES-59 pin-outs, 4-40 retaining screw

Phoenix screw block Pin-outs as indicated by connector labeling

Specification Complies with EBU-R68 / SMPTE RP-155

Impedance Load 10 k ohm

Dynamic Range 110 dB A-weighted

THD+N -102 dB (0.0008%) -1 dBFS, Unweighted

Frequency Response +0, -0.1 dB, 20 Hz/20 kHz Ref. 1 kHz

Max Level In +24 dBu

Trim Range 118 dB -96 to +22 dB in 1 dB steps

Word Clock In/Out/Thru

Specification AES-11 2009 Annex B
Connector Type BNC
Termination	75 ohm (in/out)	THRU is unterminated
Lock Range	44.1 kHz / 48kHz, +- 0.5%	x1/x2/x4
Input	1 vpp to 3 v p-p (with termination)	AC coupled
Output	5.0 vpp, (2.5 v p-p terminated)	DC coupled
Jitter	complices with AES3-4-2009	< 0.025 UI

Power Supply

Connector Type IEC 3-conductor receptacle		For AC mains connection
Configuration	Internal, Universal
Power Input	100 V to 240 V, 50 Hz or 60 Hz

Power Usage 35 watts

APPENDIX c Mixer Schematics

MONO INPUT CHANNEL

graph TD
    A["HPF"] --> B["GATE"]
    B --> C["EQ"]
    C --> D["COMP"]
    D --> E["POST FX"]
    D --> F["MUTE"]
    F --> G["FADER"]
    G --> H["SEND"]
    H --> I["PAN"]
    I --> J["L MAIN MIX"]
    I --> K["R"]
    G --> L["PAN"]
    L --> M["L GROUP REVERB STEREO AUX"]
    L --> N["R"]
    G --> O["POST"]
    G --> P["PRE"]
    G --> Q["POST"]
    G --> R["PRE"]
    G --> S["POST"]
    G --> T["MONO AUX"]
    U["SOLO BUS"] --> V["PAN"]
    V --> W["POST"]
    X["POST"] --> Y["SEND"]
    Y --> Z["PAN"]
    Z --> AA["L GROUP REVERB STEREO AUX"]
    AB["POST"] --> AC["SEND"]
    AC --> AD["PAN"]
    AD --> AE["L GROUP REVERB STEREO AUX"]
    AF["POST"] --> AG["MONO AUX"]

STEREO INPUT CHANNEL

graph TD
    A["HPF"] -->|2| B["GATE"]
    B -->|2| C["EQ"]
    C -->|2| D["COMP"]
    D -->|2| E["POST FX"]
    D -->|2| F["SOLO BUS"]
    E --> G["FADER"]
    F --> G
    G --> H["SEND"]
    H --> I["MAIN MIX"]
    G --> J["PRE"]
    J --> K["POST"]
    J --> L["SEND"]
    L --> M["GROUP REVERB STEREO AUX"]
    L --> N["MONO AUX"]
    N --> O["POST"]
    O --> P["POST"]
    P --> Q["POST FX"]
    Q --> R["MUTE"]

GROUP BUS

graph TD
    EQ --> LEVELER
    LEVELER --> MUTE
    MUTE --> FADER
    FADER --> GROUP_OUT
    FADER --> MAIN_MIX
    FADER --> GROUP_REVERB_STEREO_AUX
    FADER --> PRE
    PRE --> POST
    POST --> PRE
    PRE --> POST
    PRE --> POST
    POST --> MONO_AUX
    PRE --> 1
    PRE --> 1
    PRE --> 2
    PRE --> 2
    style EQ fill:#f9f,stroke:#333
    style LEVELER fill:#ccf,stroke:#333
    style MUTE fill:#cfc,stroke:#333
    style FADER fill:#ffc,stroke:#333
    style PRE fill:#fcc,stroke:#333
    style PRE fill:#cff,stroke:#333
    style POST fill:#fcf,stroke:#333
    style PRE fill:#fcf,stroke:#333
    style POST fill:#fcf,stroke:#333
    style PRE fill:#cff,stroke:#333
    style POST fill:#fcf,stroke:#333
    style PRE fill:#fcf,stroke:#333
    style PRE fill:#cff,stroke:#333
    style POST fill:#fcf,stroke:#333
    style PRE fill:#cff,stroke:#333
    style POST fill:#fcf,stroke:#333
    style PRE fill:#fcf,stroke:#333
    style PRE fill:#cff,stroke:#333
    style POST fill:#fcf,stroke:#333
    style PRE fill:#fcf,stroke:#333
    style POST fill:#fcf,stroke:#333
    style PRE fill:#cff,stroke:#333
    style POST fill:#fcf,stroke:#333
    style PRE fill:#fcf,stroke:#�33
    style POST fill:#fcf,stroke:#333
    style PRE fill:#cff,stroke:#333
    style POST fill:#fcf,stroke:#333
    style PRE fill:#fcf,stroke:#333
    style POST fill:#fcf,stroke:#333
    style PRE fill:#cff,stroke:#333
    style POST fill:#fcf,stroke:#333
    style PRE fill:#fc f,stroke:#333
    style POST fill:#fc f,stroke:#333
    style PRE fill:#fc f,stroke:#333
    style POST fill:#fc f,stroke:#333
    style PRE fill:#cff,stroke:#333
    style POST fill:#fc f,stroke:#333
    style PRE fill:#fc f,stroke:#333
    style POST fill:#fc f,stroke:#333
    style PRE fill:#cff,stroke:#333
    style POST fill:#fc f,stroke:#333

MONITOR BUS

graph TD
    A["SOLO"] --> B["IN 1"]
    B --> C["SOLO"]
    C --> D["GROUP 1"]
    D --> E["SOLO BUS"]
    E --> F["SOLO SELECT"]
    F --> G["MONITOR ASSIGN"]
    G --> H["ANY SOLOED"]
    H --> I["FOLLOW SOLO ON"]
    I --> J["FOLLOW SOLO OFF"]
    J --> K["MONITOR OUT"]
    F --> L["AUX 1"]
    F --> M["AUX 7"]
    F --> N["AUX 2"]
    F --> O["AUX 2"]
    F --> P["AUX 2"]
    F --> Q["AUX 2"]
    F --> R["AUX 2"]
    F --> S["AUX 2"]
    F --> T["AUX 2"]
    F --> U["AUX 2"]
    F --> V["AUX 2"]
    F --> W["AUX 2"]
    F --> X["AUX 2"]
    F --> Y["AUX 2"]

APPENDIX D D-sub Connector Specifications

D-SUB CABLE PIN-OUTS

The 24Ai and 24Ao follow the Panasonic/Tascam (AES-59) standard specification for a female D-sub connector with balanced analog input or output.

ANALOG DB25 8 CHANNEL BALANCED IN OR OUT

The 24Ai and 24Ao D-sub connectors are equipped with standard nuts with a 4-40 thread size, which support 4-40 retaining screws. When you purchase your DB-25 cable, most DB-25 cables include 4-40 screws, but they may not be installed on the cable yet. Instead, the cable may have metric screws on it, with the 4-40 screws supplied separately (in a bag or pouch). If this is the case, remove the currently installed screws and replace them with the supplied 4-40 screws.

Use 4-40 retaining screws (supplied with your DB-25 cable)

Pin Signal

1 Channel 8 (+)
2 SG (Signal Ground)
3 Channel 7 (-)
4 Channel 6 (+)
5	SG
6 Channel 5 (-)
7 Channel 4 (+)
8	SG
9 Channel 3 (-)
10 Channel 2 (+)
11 SG
12 Channel 1 (-)
13 Not used
14 Channel 8 (-)
15 Channel (7 (+)
16 SG
17 Channel 6 (-)
18 Channel 5 (+)
19 SG
20 Channel 4 (-)
21 Channel 3 (+)
22 SG
23 Channel 2 (-)
24 Channel 1 (+)
25 SG

APPENDIX E Updating Firmware

MOTU periodically posts firmware updates for your MOTU AVB interface. These updates may include bug fixes, enhancements, and new features.

Updates are posted on MOTU's servers. If your computer or Wi-Fi device has access to the internet, the MOTU AVB Control app notifies you as soon as an update is made available. Otherwise, you can check motu.com/avb periodically for the latest firmware update.

A network cable connection is required

Firmware updating requires a network cable connection, so before you begin, connect a standard CAT-5 or CAT-6 network cable from the network port on your MOTU interface to one of the following:

• Your computer's network port (or a Thunderbolt-to-Ethernet adapter)
  ■ Your home, studio, or office network (with internet access)
  ■ An AVB port on a MOTU AVB switch (connected to your office network through the Ethernet port)

Updating with internet access

You are now ready to update:

1 Launch the MOTU AVB Control web app on your computer, iPad, or iPhone, as usual.
2 Go to the Device tab.
3 In the New Update Available banner (Figure E-1), click More Info.
4 After reviewing the list of enhancements, click OK to start the update.
5 Wait a few moments for the update to finish, then click OK to return to the Device tab.
6 IMPORTANT: disconnect the Ethernet cable from your MOTU interface after you complete the update, unless it is connected to a MOTU AVB switch or other AVB-aware switch. If so, you can leave it connected.

MOTU 16A Device Routing Mixing Aux Mixing New Update Available (1.0.1) More Info Configuration Sample Rate: 48000

Figure E-1: The firmware update banner appears automatically at the top of the Device tab when your web host has internet access and MOTU posts an update.

Updating off-line, without internet access

If your MOTU AVB interface (and the computer it is connected to) has no internet access, you can download a firmware update file from another computer that does have internet, and then use the file to update your MOTU interface, as follows:

1 Download the firmware file.
2 Transfer the file to a computer with a network cable connection to your MOTU interface.
3 Launch the MOTU AVB Control web app on the computer, as usual.
4 Go to the Device tab.
5 Scroll down to the bottom and click Update from File.
6 Locate the file on your hard drive and click OK to start the update.
7 Wait a few moments for the update to finish, then click OK to return to the Device tab.
8 IMPORTANT: disconnect the Ethernet cable from your MOTU interface after you complete the update, unless it's connected to a MOTU AVB switch or other AVB-aware switch. If so, you can leave it connected.

Viewing the latest firmware version information

You can confirm the firmware version at the bottom of the Device tab (Figure E-2).

Why does the firmware update require a network cable?

Firmware updating was designed to use ethernet mostly for convenience. If you have lots of networked devices, you can upgrade them all from a distance (even over Wi-Fi) without having to plug in directly and without having to download or run an updater application.

This approach was also taken for engineering reasons, with reliability foremost in mind. When installing an update, the device reboots into a stripped-down recovery partition to guarantee that the update process can always be completed, even if the power goes out mid-update. Since updates can also affect the Thunderbolt or USB chips, they cannot be used during the update.

Manufacturer	Model	GUID	Firmware Version	UI Version	Hostname
MOTU	8M	0001f2fffe0002d0	1.0.1+771	1.0.1+63807	8M

Figure E-2: The currently installed firmware version is displayed at the bottom of the Device tab.

APPENDIX F OSC Support

Open Sound Control (OSC) is a protocol for communication among computers and other multimedia devices that is optimized for modern networking technology.

MOTU AVB audio interfaces support OSC, which provides remote control of all device settings and mixer controls from any OSC-enabled controller.

For further details about remote control through OSC, along with complete documentation for the MOTU AVB OSC API, visit:

http://www.motu.com/avb#avb-osc-support

24Ai

expansion 34

front panel 9

installing 33

rear panel 10

summary of features 23

24Ao

expansion 34

front panel 11

installing 33

rear panel 12

summary of features 23

24-bit

optical 10, 12

2x SMUX mode 15,40

Ableton Live 55, 58

ADAT optical 10, 12

connecting 40

SMUX Type 54

Analog inputs/outputs 40

Apple

Garage Band 58

Logic Pro 58

ASIO Buffer Size 30

ASIO monitoring 59

Attack

Compressor 64, 65

Audio interface preset 7, 47

AudioDesk 25, 31, 55, 58

authenticating 77

Aux Mix Target 18

Aux Mixing tab 18

AVB

audio interface operation 24

Discovery app 7, 30

Ethernet explained 69

Input/Output Banks 15

networking 69-74

overview 69

Stream Connections 15

Stream Setup 15

streams (Routing tab) 16

Switch

setup 35, 39

AVB Control web app 7, 13-22

Aux Mixing tab 18

Device tab 14, 15

Mixing tab 17

Routing tab 16

Avid

Pro Tools 58

Become Clock Master 14, 42

CAT-5e/6 cables 34

Check for Updates 15

Chrome 13

Class compliance 29

Clock section (LCD) 54

Clock source 14, 40

Cockos Reaper 58

Compressor effect 17,65

Computer Setup 15

Connecting multiple interfaces 34

Control Panel 30, 60

Control surface support (through OSC) 89

Converter mode

setup/example 51

Core Audio driver 58

Cubase 55, 58

clock source 55

sample rate 55

Customer

support 78

Device tab 14, 15

Digital converter (see Optical converter)

Digital Performer 55, 58

Direct hardware playthrough 59

Direct ASIO monitoring 59

Direct hardware playthrough 59

Driver installation 7, 13, 29

Drivers

installing USB drivers 30

DSP

effects 63

meter 68

resources 68

DSP Usage 19,68

Effects 63

EQ 64

enabling 64

filter types 64

frequency 64

gain 64

Q64

Ethernet

connecting 39

Expansion 34

Firefox 13

Firmware updates 14

Follow Solo 17, 20

Force 1x Clock setting 42

Four-band EQ 64

Frequency

EQ 64

From Computer 16

Front panel 53

menu navigation 53

metering 53

Gain

EQ 64

reduction 65

reduction (Leveler) 67

Garage Band 55, 58

clock source 55

sample rate 55

Gate effect 17, 64

GR (gain reduction) 65

High pass filter 63

Host audio software

3rd party software sync 61

ID knob/button 13, 14, 53

IEEE 802.1 69

Input banks 15

Input settings 14

Inputs

optical 10, 12

Installation

AVB audio interface 34

hardware 33

network 35, 36

QuickStart Guide 7

software 30

Thunderbolt interface 33

two interfaces networked 34

Interface + mixer preset 7, 48

Internet Explorer 13

IP address 13

iPad

QuickStart 7

Latency 59,61

LCD

menu 53

Leveler 17, 66

Lightpipe 40

2x mode 54

Limit button 67

Live 58

Live recording with monitor mixing preset 7,49

Logic Pro 58

Logic Pro/Express 55

clock source 55

sample rate 55

Mac OS X 55

input and output names 57

system requirements 27

Makeup gain 67

Mixer

accessing 17

aux bus 21

effects 63

group bus 22

input channel strip 19

main mix channel strip 20

Monitor channel strip 20

overview 17

Reverb bus 22

schematics 81

Setup 15

stand-alone operation 63

Mixing tab 17

MOTU

AudioDesk 58

AVB Control web app 7, 13-22

Aux Mixing tab 18

Device tab 14, 15

Mixing tab 17

Routing tab 16

AVB Discovery app 7, 30

AVB Installer 7, 29

AVB Switch

setup 35, 39

Digital Performer 58

MOTU AVB

Control web app 13

Discovery app 13

Installer 13

USB ASIO driver 58

WebUI Setup 13

MOTU AVB WebUI Setup 30

Networking 69-74

installation 35, 36

Nuendo 55, 58

clock source 55

sample rate 55

Optical

2x mode 54

connectors 10, 12, 40

S/PDIF 40

Optical converter mode 54

setup/example 51

Optical Converter preset 7, 51

Optical setup 15

Optimization 61

OS X audio software

clock source 55

sample rate 55

OSC support 89

Output banks 15

Outputs

optical 10, 12

Packing list 27

Patch thru

latency61

Performance 61

Phase-lock 41

PRE switch 17

PreDelay 67

Prefader button 18

Presets 7, 14

Mixer tab 17

overview 47

Routing tab 16

Pro Tools 55, 58

Processing 63

Q 64

Quick Setup window 7

QuickStart Guide 7

Ratio

Compressor 65

Reaper 55, 58

Reason 55

Propellerhead Reason 58

Record 55

Registration 27

Release

Compressor 64, 65

Remote control (through OSC) 89

Restore Factory Presets 15

Reverb 67-68

design section 67

enabling/disabling 67

predelay 67

routing to/from 67

time 67, 68

width 68

RMS mode 65

Routing tab 16

S/MUX 54

S/PDIF (optical) 40

Safari 13

Sample rate 14

SC button 20

Schematics 81

SMUX 40

Software

installation 30

Software installer 7, 13, 29

Solo bus 20

Solo Clear button 19

SONAR 55

Soundtrack Pro

clock source 55

sample rate 55

Stage I/O preset 7, 49

Stand-alone mixer preset 7, 48

Stand-alone operation 53, 54

Standard (optical setting) 40

Steinberg

Cubase 58

Nuendo 58

Studio Input Expander preset 7, 50

Studio Output Expander preset 7, 50

Synchronization 40

Become Clock Master 42

host software 61

System requirements

minimum 27

recommended computer 27

Technical support 78

Threshold

Compressor 65

To Computer 16

TOSLink 40

Troubleshooting 77

TRS analog inputs/outputs 40

Type I, II optical mode 54

Type II (Legacy) optical setting 40

Update From File 15

USB

class compliance 29

installing drivers 30

USB Streaming Mode 30

View Personal Mix 18

Wave driver 58

Width

reverb 68

WiFi

setup 39

Windo

shortcut 30

system requirements 27

Word clock

Force 1x Clock setting 42