Voice Channel - Processor ART - Free user manual and instructions

Product Type	Tube Microphone Preamplifier / Voice Processor
Brand	ART
Model	Voice Channel
Form Factor	1U Rackmount
Inputs	Balanced XLR (Microphone), Unbalanced 1/4" TS (Instrument)
Outputs	Balanced XLR, Unbalanced 1/4" TS
Preamp Type	Vacuum Tube (12AX7)
Compression	Variable Ratio, Threshold, Attack, Release, Hard/Soft Knee
Equalization	3-Band: Low Shelf, Parametric Mid, High Shelf
De-esser	Fixed frequency de-esser with threshold control
Output Level Control	Master volume with VU meter
Phantom Power	+48V, switchable
Power Supply	Internal, 120V AC (230V AC for export models)
Dimensions (W x D x H)	19" x 6.5" x 1.75" (482 x 165 x 44 mm)
Weight	5.0 lbs (2.27 kg)
Frequency Response	10 Hz - 40 kHz (±0.5 dB)
Signal-to-Noise Ratio	>100 dB (A-weighted)
THD+N	<0.01% (typical)
Cleaning	Wipe with dry cloth; avoid solvents; keep vents clear
Safety	Use grounded outlet; do not expose to moisture; no user-serviceable parts inside
Spare Parts	Contact ART support for replacement tubes (12AX7) and power supply
Reparability	Serviceable by qualified technician; vacuum tube replacement can be done by user with caution

Frequently Asked Questions - Voice Channel ART

How do I connect a microphone to the ART Voice Channel?

Connect an XLR microphone cable to the MIC INPUT on the rear panel. Ensure phantom power (+48V) is enabled if using a condenser microphone. Set the input gain appropriately.

Can I use the Voice Channel as an instrument preamp?

Yes, connect your instrument (e.g., guitar or bass) to the INSTRUMENT INPUT using a standard 1/4" TS cable. This input has high impedance for direct connection.

How do I adjust the compression settings?

The compression section has controls for THRESHOLD, RATIO, ATTACK, RELEASE, and KNEE. Start with a low ratio (e.g., 2:1) and adjust threshold until gain reduction occurs. Set attack and release according to your source material.

What does the de-esser do?

The DE-ESSER reduces sibilant sounds (like "s" and "sh") in vocal recordings. Adjust the threshold to reduce sibilance without dulling the overall sound.

How do I replace the vacuum tube?

Turn off the unit and disconnect power. Remove the top cover screws and locate the 12AX7 tube. Carefully pull it out and replace with the same type. Reassemble. No adjustment needed.

Why is there no sound from the output?

Check that the POWER switch is on, input cables are connected, and the MASTER VOLUME is turned up. Ensure phantom power is off for dynamic mics. Verify the output is connected to an active amplifier or mixer.

Can I use the Voice Channel for recording vocals?

Absolutely. The Voice Channel is designed for vocal processing. Connect a microphone, apply compression and EQ as needed, and route the output to your audio interface or mixer.

How do I clean the unit?

Use a soft, dry cloth to wipe the exterior. Avoid liquid cleaners, as they may damage the controls or internal components. Keep the ventilation slots free of dust.

What is the proper storage condition?

Store in a cool, dry place away from direct sunlight and extreme temperatures. Use a rack or case to protect it from physical damage.

Is the ART Voice Channel compatible with 230V AC power?

The unit is available in 120V and 230V versions. Check the label near the power cord for your model. Do not connect to a voltage different from what is specified.

USER MANUAL Voice Channel ART

Tube Channel Strip with Digital Connectivity

SERVICE MANUAL

APPLIED RESEARCH AND TECHNOLOGY

IMPORTANT SAFETY INSTRUCTIONS – READ FIRST

This symbol, wherever it appears. This symbol, wherever it appears, alerts alerts you to the presence of uninsulated you to important operating and maintenance dangerous voltage inside the enclosure. Voltage instructions in the accompanying literature that may be sufficient to constitute a risk of shock. Please read manual.

Read instructions:

Retain these safety and operating instructions for future reference. Heed all warnings printed here and on the equipment. Follow the operating instructions printed in this user guide.

Do not open:

Aside from one vacuum tube, there are no user serviceable parts inside. Refer any service work to qualified technical personnel only.

Power sources:

Only connect the unit to mains power of the type marked on the rear panel. The power source must provide a good ground connection.

Power cord:

Use the power cord with sealed mains plug appropriate for your local mains supply as provided with the equipment. If the provided plug does not fit into your outlet consult your service agent. Route the power cord so that it is not likely to be walked on, stretched or pinched by items placed upon or against.

Grounding:

Do not defeat the grounding and polarization means of the power cord plug. Do not remove or tamper with the ground connection on the power cord.

Ventilation:

Do not obstruct the ventilation slots or position the unit where the air required for ventilation is impeded. If the unit is to be operated in a rack, case or other furniture, ensure that it is constructed to allow adequate ventilation.

Moisture:

To reduce the risk of fire or electrical shock do not expose the unit to rain, moisture or use in damp or wet conditions. Do not place a container of liquid on it, which may spill into any openings.

Heat:

Do not locate the unit in a place close to excessive heat or direct sunlight, as this could be a fire hazard. Locate the unit away from any equipment, which produces heat such as: power supplies, power amplifiers and heaters.

Environment:

Protect from excessive dirt, dust, heat, and vibration when operating and storing. Avoid tobacco ash, drink spillage and smoke, especially that associated with smoke machines.

Handling:

To prevent damage to the controls and cosmetics avoid rough handling and excessive vibration. Protect the controls from damage during transit. Use adequate padding if you need to ship the unit. To avoid injury to yourself or damage to the equipment take care when lifting, moving or carrying the unit.

Servicing:

Switch off the equipment and unplug the power cord immediately if it is exposed to moisture, spilled liquid, objects fallen into opening, or the power cord or plug becomes damaged during a lightning storm or if smoke odor or noise is noted. Refer servicing to qualified technical personnel only.

Installation:

Install the unit in accordance with the instructions printed in the user guide.

Voice Channel

Tube Channel Strip with Digital Connectivity

IMPORTANT SAFETY INSTRUCTIONS – READ FIRST ....1

INTRODUCTION......4

INSTALLATION....4

AC Power Hookup 4

Analog Audio Connections 4

USB OPERATION 5

FRONT PANEL CONTROLS and JACKS......6

Mic Preamp Controls....6

Instrument Input 6

Gain Control 6

Impedance Control....6

Pad Switch 6

Phantom Power 6

Invert Switch....6

Low Cut Switch....6

Tube Voltage Switch 7

Dynamic Processor Controls 8

Threshold Control....8

Ratio Control 8

De-esser Control 8

De-esser Freq. Control....8

Attack Control....8

Release Control....9

Gain Reduction LED Meter....9

Expander/Gate Switch....9

Expander/Gate Threshold Control....9

Semi-Parametric EQ 10

EQ Position Switch....10

EQ Bypass Switch....10

Output Level Control 11

Output Level Meters 11

Sample Rate/Dither Control....12

Optical Output Switch....12

REAR PANEL CONNECTIONS....13

Mic/Line Input....13

Mic Preamp Output 13

Insert Input 13

Balanced Output....13

A/D Main Insert and A/D CH2 Insert....13

Wordclock Input and Thru Jacks 13

ADAT Input Jack 14

Optical Output Jack....14

S/PDIF Output Jack....14

AES/EBU Output Jack....14

USB Jack....14

APPLICATIONS 15

Bypassing Components Of The Voice Channel™ 15

Optimizing The Preamp For Lowest Noise....15

Utilizing Pre/Post Compression EQ....15

SERVICE PARTS 16

FULL BILL OF MATERIALS 19

SCHEMATICS....28

WARRANTY INFORMATION....32

Limited Warranty (USA only) 32

Online Registration 32

Exclusions 32

SERVICE 33

SPECIFICATIONS....34

LIST OF FIGURES

FIGURE 1 – Preamp section ....7

FIGURE 2 – Dynamics Section....7

FIGURE 3 - Equalizer Section ...... 10

FIGURE 4 – Signal Flow Block Diagram ...... 11

FIGURE 5 – Output Section ...... 12

FIGURE 6 - Rear Panel 12

FIGURE 7 - Wordclock Termination....14

INTRODUCTION

The ART Voice Channel is the answer to your recording and computer audio interface needs. Our second-generation discrete Class-A microphone preamp provides clean quiet gain while maintaining incredible transparency. A powerful dynamics processor subtly controls transients and noise of the most demanding sources. The ART Voice Channel's semi-parametric EQ offers wide tune-ability and can be patched before OR after the dynamics processor. Separate insertion jacks allow you to use your favorite external signal processing gear immediately after the Mic preamp and before the EQ and dynamics processor. Another patch point exists just before the A/D converters. Choose between a wide range of outputs including balanced analog output, 44.1 KHz to 192 KHz AES/EBU, S/PDIF, ADAT and USB. Both analog and digital meters provide a detailed indication of audio levels.

INSTALLATION

The ART Voice Channel may be used in a wide variety of applications and environments. In a rack-mountable, all-steel enclosure, the unit is designed for continuous professional use. Mounting location is not critical, however for greater performance reliability we recommend that you not place the unit on top of power amps, or other sources of heat and/or strong magnetic fields. The tube circuitry needs about a minute to “warm up” and stabilize from a cold power up.

AC Power Hookup

The ART Voice Channel has an internal power supply. Only connect the unit to mains power of the type marked on the rear panel. The power source must provide a good ground connection, and the ground pin on the mains plug should never be defeated.

Analog Audio Connections

Audio connections to and from the Voice Channel are:

Front panel balanced combo input: [XLR] Pin 2 = Hot (+), Pin 3 = Cold (-), Pin 1 = Ground [1/4-inch] Tip = Hot (+), Sleeve = Ground

Rear panel balanced combo input: [XLR] Pin 2 = Hot (+), Pin 3 = Cold (-), Pin 1 = Ground [1/4-inch] Tip = Hot (+), Ring = Cold (-), Sleeve = Ground

Rear panel balanced 1/4" output: Tip = Hot (+), Ring = Cold (-), Sleeve = Ground

Rear panel 1/4" insert input: Tip = Hot (+), Sleeve = Ground

Mic Preamp Output: Tip = Hot (+), Sleeve = Ground

A/D Main & A/D CH2 Inserts: Tip = Input, Ring = Output, Sleeve = Ground

USB OPERATION

Connect your analog jacks and power up the unit first. Next, set the front panel controls for proper operation as per the previous sections. Then connect the USB cable to the appropriate input on your computer and lastly to the USB connector on the Voice Channel.

Once the USB connection is made and your computer is on, the unit will automatically connect and try to set your computer “Default Audio Device” to be “USB Audio CODEC”. Usually the computer will do this automatically whenever a USB device is first connected, but it is sometimes necessary to make the selection manually. The same settings may need to be made in your particular audio application as well (Check your application instructions). These settings should be made while the Voice Channel and computer are connected and powered on.

FRONT PANEL CONTROLS and JACKS

Mic Preamp Controls

The Voice Channel input consists of a discrete Class-A differential preamp. The circuit is optimized for low impedance microphones as well as line level signals. Up to 60dB of gain is available from this stage. The output can be inverted using the INVERT switch.

The impedance of the front and rear XLR inputs is continuously variable for fine-tuning the preamp to a wide variety of mics. Phantom power is available on the XLR inputs as well.

A selectable low-cut filter removes rumble, wind noise, and pops, thereby increasing clarity.

Instrument Input

The 14 -inch T/S jack on the front panel provides a high impedance unbalanced input, and when used, automatically switches off the mic pre-amp. (The rear combo jack's 14 -inch T/R/S balanced input is lower impedance and is part of the mic pre-amp. The rear jack is not intended to be used with high impedance microphones or instruments.) NOTE: When using the INSTRUMENT INPUT, the PAD switch is disabled and does NOT affect the gain.

Gain Control

This control adjusts both the mic pre-amp gain as well as the instrument input gain. The gain marked applies to the mic pre-amp without the PAD switch depressed. The instrument input gain markings are on the right side of the slash (/). Refer to the APPLICATIONS section to learn how to optimize the gain control for low noise operation.

Impedance Control

This knob sets the load impedance at the front and rear panel XLR inputs of the Voice Channel. Use the IMPEDANCE CONTROL to subtly tune the sound of your microphone. Various microphones will change their sound at differing load impedances. The correct setting is subjective. Adjust this control to personal taste.

Pad Switch

This switch reduces the mic pre-amp gain by up to 20dB to prevent clipping when high level mic, or line level signals are applied to the balanced XLR or 14 -inch T/R/S inputs. This switch does NOT affect the 14 -inch T/S front panel INSTRUMENT INPUT.

Phantom Power

The switch safely applies +48Volt phantom power to the XLR inputs. Use phantom power only when the microphone that you are using requires it. Doing so will extend the life of the Voice Channel as well as reducing the possibility of shock hazard.

Invert Switch

This switch selects the output phase of the Voice Channel. There is a 180 degree phase shift through the Voice Channel ^™ when lit.

Low Cut Switch

This switch inserts a 100Hz 6dB/Oct. Low-Cut filter into the signal path. The filter is designed to remove rumble, pops, and wind noise, yet still sound natural.

FIGURE 1 – Preamp section

Tube Voltage Switch

The vacuum tube preamp section can be adjusted to run at two different plate voltages. Refer to Figure 2 for the location of the switch.

Choose the “NORMAL” setting for adding warmth to the input signal. This setting has an increased amount of tube saturation at higher signal levels.

Choose the "HIGH" setting to increase overall gain, headroom, and bandwidth.

NOTE: The change between tube voltage modes is gradual, taking 10 to 20 seconds to be fully activated.

FIGURE 2 – Dynamics Section

Dynamic Processor Controls

The ART Voice Channel dynamics section consists of an above threshold Compressor/Limiter with De-esser plus a selectable Expander/Gate. The attack and release controls allow a wide range of adjustment while the complex detector assures fast response without distortion. The De-esser is frequency tunable.

Threshold Control

This control sets the level, above which the Compressor/Limiter in the Voice Channel starts to act on the input signal. As the control is turned clockwise, more input signal is required to begin reducing gain. The compression action can be seen in the Gain Reduction LED meter.

Ratio Control

The RATIO control sets the amount of gain reduction that takes place based on how far the input signal is over the threshold level (set by the THRESHOLD control). When the control is fully counterclockwise, the Compressor/Limiter is OFF.

A good starting point for vocals is 2.5:1.

To have the unit act as a limiter, set the RATIO control to 20:1.

De-esser Control

The DE-ESSER control sets how much more the gain is reduced at high frequencies when using the Compressor/Limiter. The most common application is reducing sibilance when compressing vocals. When fully counterclockwise, the De-esser function is OFF. As the control is turned clockwise, high frequency material is compressed more than mid and low frequency material.

De-esser Freq. Control

This control selects which high frequencies the DE-ESSER acts upon. Turned fully counterclockwise, the DE-ESSER acts on the upper mid-range. When set fully clockwise, only the highest frequencies are reduced more during de-essing compression. Center the DE-ESSER FREQ. control as a starting point for vocal work.

Attack Control

The ATTACK control sets the time it takes the Compressor/Limiter to respond to increases in signal level (by reducing gain). You can use this control to shape the “front end” of the dynamics envelope.

One example is to listen to a snare hit and adjust the attack control. A short attack makes the snare sound "thin". As the attacks go longer (and the knob is turned clockwise) you should hear more of the thump in the compressed snare. The downside is that this creates an overshoot, (a large transient), the length of which is the time set by the ATTACK control.

Overshoots less than 1 msec are very hard to hear even when they are clipped. If the attack is set too fast, the gain may be reduced too much and thereby create a “pumping” sound ^1 . One way to eliminate this is to use the LOW CUT filter to remove plosive sounds in vocals that can make the detector overreact.

Release Control

The RELEASE control sets the time the Compressor/Limiter takes to increase the gain after the input level drops.

Longer settings maintain the dynamics of the input signal, while shorter settings reduce the dynamics. Shorter settings will also increase the apparent reverberation, and at extreme gain reduction settings, lead to "breathing" artifacts ^2

Gain Reduction LED Meter

The GAIN REDUCTION meter displays the Compressor/Limiter's attenuation action. The meter covers a very large range while offering high resolution.

The large yellow LED at the right-hand end of the meter indicates Expander or Gate action. The brightness of the LED indicates the amount of gain reduction for the Expander function. Since the Gate is either ON or OFF, there is no brightness variation.

Expander/Gate Switch

This switch allows the selection of the Expander or the Gate functions. Both are useful in reducing unwanted background noise in the audio signal.

In the "OUT" position the Expander function is selected. Use this mode to gradually reduce background noise and maintain some of the input dynamics. This is useful for instruments with gradually decaying amplitude envelopes.

Depress this switch to select the Gate mode. This mode quickly cuts off the noise as the input signal drops.

Expander/Gate Threshold Control

The Expander/Gate action begins below the level indicated by the EXPANDER/GATE THRESHOLD control. The EXPANDER/GATE THRESH. LED in the GAIN REDUCTION display will light when the Expander or Gate attenuates the input signal.

The Expander/Gate Threshold detector has built-in hysteresis, which causes the unit to trigger "ON" at a higher level than the level required to trigger back to the "OFF" state.

The Expander slope is about 1:1.5. This is subtle enough to maintain the decay envelope of the source material and still lower the noise as the input signal drops. The EXPANDER/GATE THRESH. LED will light dimly for the first 5dB of gain reduction, and then glow brightly as the attenuation increases above this level.

The Gate function has an intelligent detector with a fast “attack” and “release”, coupled with a program dependant “hold”. The hold time is longer for sustained passages and shorter for transients. As the input drops below the threshold and the input signal is muted, the EXPANDER/GATE THRESH. LED lights brightly.

You can turn off the Expander/Gate function by setting the THRESHOLD control fully counterclockwise to "OFF".

Semi-Parametric EQ

The ART Voice Channel offers a four-band semi-parametric equalizer. The EQ can be bypassed as well as positioned before or after the dynamics processing section. Each band has ± 15dB of control range.

The High and Low EQ bands are shelving type with a switch selectable turnover point.

The two Mid bands can be continuously tuned over a five octave range.

FIGURE 3 – Equalizer Section

EQ Position Switch

The EQ POSITION switch allows you to connect the EQ before or after the dynamics processing block. This is useful in cases where the input signal needs a great deal of EQ before the Compressor/Limiter processes it. One example of using the EQ in the “PRE” position is using the LOW EQ control as a tunable low frequency cut, supplementing the LOW CUT filter switch.

Refer to Figure 4 for the block diagram of the Tube Channel. Note that the Mic preamp insert jack function is located before the EQ position switch.

EQ Bypass Switch

This switch allows you to instantly set the EQ completely flat without loosing the current EQ settings.

graph TD
    A["PHANTOM POWER"] --> B["INPUT: 28/6dB"]
    C["PAD"] --> D["20/3dB"]
    D --> E["GAIN: 43/18dB"]
    E --> F["Instrument pre-omp"]
    F --> G["TUBE VOLTAGE"]
    G --> H["Tube gain stage"]
    H --> I["LOW CUT"]
    I --> J["INVERT"]
    J --> K["OUTPUT OUTPUT"]
    K --> L["PRE"]
    L --> M["POST"]
    M --> N["DYNAMICS PROCESSOR"]
    N --> O["PRE"]
    O --> P["POST"]
    P --> Q["OUTPUT BUFFER"]
    Q --> R["OUTPUT LEVEL"]
    S["IMPEDANCE"] --> T["368 1.2K"]
    T --> U["150 3K"]
    U --> V["Micro pre-omp"]
    V --> W["Phantom"]
    X["INVERT"] --> Y["Inverter"]
    Z["EQ PRE/POST"] --> AA["EQ"]
    AB["BALANCED OUTPUTS"] --> AC["LEFT A/D INSERT"]
    AD["SAMPLE RATE/DITHER"] --> AE["A/D converter"]
    AF["USB A/D converters"] --> AG["S/PDIF AES/EBU ADAT OUTPUTS"]
    AH["RIGHT A/D INSERT"] --> AI["USB A/D OUTPUT"]
    AJ["MIX PREAMP OUTPUT"] --> AK["PRE"]
    AL["INSERT INPUT"] --> AM["POST"]
    AN["DYNAMICS PROCESSOR"] --> AO["PRE"]
    AP["BANANCED OUTPUTS"] --> AQ["A/B/A/B", "A/B/A/B", "A/B/A/B", "A/B/A/B", "A/B/A/B", "A/B/A/B", "A/B/A/B", "A/B/A/B", "A/B/A/B", "A/B/A/B", "A/B/A/B", "A/B/A/B", "A/B/A/B", "A/B/A/B", "A/B/A/B", "A/B/A/B", "A/B/A/B", "A/B/A/C", "A/B/A/C", "A/B/A/C", "A/B/A/C", "A/B/A/C", "A/B/A/C", "A/B/A/C", "A/B/A/C", "A/B/A/C", "A/B/A/C", "A/B/A/C", "A/B/A/C", "A/B/A/C", "A/B/A/C", "A/B/A/C", "A/B/A/C", "A/B/A/C", "A /B /B /C" --> AB

FIGURE 4 – Signal Flow Block Diagram

Output Level Control

The OUTPUT LEVEL control provides gain or attenuation to adjust for a variety of system operating levels. This control affects the levels sent to the A/D converter and to the balanced analog OUTPUT jacks.

Output Level Meters

The ART Voice Channel provides both analog and digital output meters. The meters monitor the signal level just after the output control. This signal is sent to both the analog and digital outputs.

"0" VU on the analog VU meter corresponds to +4dBu on the balanced outputs, and about -20dB on the LED bargraph meter.

The LED bargraph meter indicates peak levels as well as average levels. Average levels are indicated by a continuous string of LEDs being lit. Peak levels are indicated by a single LED and are held for about 2 seconds. The last LED in the meter is marked "Clip", and it indicates that the output level is set too high.

The A/D Clip indicator LEDs act independent of the OUTPUT LEVEL meter. This provides an accurate indication of A/D converter clipping. This is useful when using the A/D insertion jacks, since the level at the converters will not be indicated on the main meters when these inputs are used.

FIGURE 5 – Output Section

Sample Rate/Dither Control

The SAMPLE RATE/DITHER knob selects the sample rate for the AES/EBU, S/PDIF, and optical outputs. It also selects the dither applied. Set the switch appropriately to match up with 16 or 24 bit encoding.

NOTE: This control does NOT affect the USB output.

Optical Output Switch

The OPTICAL OUTPUT switch sets the signal format of the rear panel OPTICAL OUTPUT connector. In ADAT mode channels 1 and 2 are the "left" and "right" A/D outputs of the Voice Channel respectively. NOTE: If the A/D insertion jacks are not being used, both channels 1 and 2 carry the same signal. If the ADAT INPUT is also being used, channels 3 thru 8 are passed through along with channels 1 and 2 of the ART Voice Channel.

FIGURE 6 – Rear Panel

REAR PANEL CONNECTIONS

Mic/Line Input

This “combo” jack provides balanced inputs to the microphone preamplifier. The XLR connection is in parallel with the front input jack XLR. The input impedance of both XLR connections is variable by the front panel Impedance knob.

The rear 14 -inch input of the combo jack overrides the front panel XLR input when used. This input's impedance is NOT affected by the front panel Impedance control and is fixed at 20K Ohms.

The Front panel Instrument input overrides the rear jack when it is used.

Mic Preamp Output

This 14 -inch T/S unbalanced jack provides a direct signal from the microphone preamplifier, ahead of the EQ and dynamics processors. This output can be used in conjunction with the INSERT INPUT jack to insert external signal processors between the main preamp section and the EQ and dynamics processing of the Voice Channel.

Insert Input

This 14 -inch T/S unbalanced jack is an input to the EQ and dynamics processing sections. This input can be used in conjunction with the MIC PREAMP OUTPUT jack to insert external signal processors between the main preamp section and the EQ and dynamics processing of the Voice Channel ^™ .

Balanced Output

The analog output of the Voice Channel is available on both a 14 -inch TRS balanced jack and an XLR jack. This output is active balanced, and will adjust to balanced or unbalanced termination without gain change. The LED and analog meter monitor the level present at this output. "0" VU on the analog meter corresponds with +4dBu (about 1.2 Volts RMS).

A/D Main Insert and A/D CH2 Insert

Signal processing can be added between the analog output of the Voice Channel and the "left" and "right" channels of the A/D converter by using the A/D MAIN INSERT and the A/D CH2 INSERT respectively. Use a 14 -inch T/R/S (stereo) cable. The Ring is the output of the preamp and the Tip is the input to the A/D converter.

In order to use just the A/D converter and not the Voice Channel preamp, simply plug a standard 14 -inch T/S phone cable into either A/D insertion jack.

Wordclock Input and Thru Jacks

The WORDCLOCK INPUT is used to externally sync the Voice Channel to a master clock source. The BNC WORDCLOCK INPUT jack is connected directly to the BNC WORDCLOCK THRU jack, providing the ability to loop through the Voice Channel and connect other devices to the wordclock sync source, saving the use of a BNC T-adapter.

The input is high impedance thus leaving the wordclock connection unterminated. (A 75 Ohm BNC terminator should be used on the WORDCLOCK THRU jack if the WORDCLOCK INPUT jack is used only by itself.)

Select the EXT/16 or EXT/24 sample rate setting on the front panel to utilize External Wordclock mode.

Refer to FIGURE 7 for wordclock termination examples.

graph TD
    A["FROM SOURCE OF WORDCLOCK SIGNAL"] --> B["WORD CLOCK INPUT"]
    C["75 Ohm TERMINATOR PLUG"] --> D["WORD CLOCK THRU"]
    B --> E["Voice Channel"]
    D --> E
    F["FROM SOURCE OF WORDCLOCK SIGNAL"] --> G["WORD CLOCK INPUT"]
    H["TO NEXT UNIT"] --> I["WORD CLOCK THRU"]
    J["WORD CLOCK INPUT"] --> K["Voice Channel"]
    L["WORD CLOCK THRU"] --> M["Voice Channel"]

FIGURE 7 – Wordclock Termination

ADAT Input Jack

The optical ADAT input allows the Voice Channel A/D converter to synchronize to systems using ADAT optical connections. The Voice Channel inserts its output in channels 1 and 2 of the ADAT stream while passing through channels 3 thru 8. Select ADAT/16 or ADAT/24 with the Sample Rate control on the front panel to enable this mode.

Optical Output Jack

The OPTICAL OUTPUT jack works in conjunction with the front panel OPTICAL OUTPUT switch, to output either an ADAT formatted signal or a TOS formatted signal. The front panel SAMPLE RATE/DITHER control sets the sample rate, dither, and sync source for this output.

S/PDIF Output Jack

This connector provides S/PDIF formatted digital outputs from the "left" and "right" A/D converters. The front panel SAMPLE RATE/DITHER control sets the sample rate, dither, and sync source for this output.

AES/EBU Output Jack

This connector provides AES/EBU signal level digital outputs from the "left" and "right" A/D converters. The front panel SAMPLE RATE/DITHER control sets the sample rate, dither, and sync source for this output.

USB Jack

The USB jack provides the output of the Voice Channel to a direct computer USB connection. The Voice Channel will be recognized as a standard audio device on the PC or Mac. The sample rate and bit depth of this interface is set by the computer and is independent of the front panel settings. The audio data formats are limited to 32 KHz, 44.1 KHz, 48 KHz, 16 or 24 bit encoding.

APPLICATIONS

Bypassing Components Of The Voice Channel

To bypass the vacuum tube microphone preamp: Use the preamp INSERT INPUT jack.

To bypass the Compressor/Limiter: Set the RATIO control fully counterclockwise to 1:1.

To bypass the Expander/Gate: Set the EXPANDER/GATE THRESHOLD control fully counterclockwise to OFF.

To bypass the EQ: Use the EQ bypass switch.

Optimizing The Preamp For Lowest Noise

The preamp of the ART Voice Channel can be optimized for low noise by combining use of the PAD and Input GAIN control for mic and line level signals. NOTE: The PAD control has no effect on the INSTRUMENT INPUT (Front panel 1/4" input of the INPUT combo jack).

First, bypass the Compressor/Limiter, Expander/Gate and EQ. Next center the OUTPUT LEVEL control to "0" dB of gain. The OUTPUT LEVEL LED meter can now be used to correctly indicate the clip level of the input stage.

Second, start with the PAD in the "OUT" position and the GAIN control centered. Refer to the OUTPUT LEVEL LED meter's peak-hold function. Make sure that this meter never indicates clipping (the red LED is held on after a transient). The peak-hold indicator can be in the "yellow" range or in the -5dB range of levels.

If the signal level is too high, depress the PAD switch.

Third, adjust the GAIN control to keep the peak levels in the -5dB range of the OUTPUT LEVEL LED meter.

Utilizing Pre/Post Compression EQ

The Equalizer section of the Voice Channel can be applied either before OR after the Compressor/Limiter. This function is useful in getting the best performance out of the unit.

Setting the Equalizer to “PRE COMP” is useful when the input signal contains too much low or high frequency information. Compressors in general work best when the audio is equalized first. (This can also serve to better control signal overshoots to the A/D converters as well.)

One example is a vocal where the performer/microphone combination produces a “popping” sound, and when compressed, the Compressor/Limiter “pumps”. Sometimes the use of the LOW CUT filter in the preamp section does not cut enough of this out, or cuts too much of the lower midrange out of the signal to be useful. Here, the EQ can surgically remove this information and better optimize the overall sound.

SERVICE PARTS

ART Part #	Value Description Footprint			Qty Location
IC PARTS SECTION
100-1134-101 LM339	AN QUAD COMPARATOR DIP14 5				U106, U107, U108, U109, U110
100-1271-101 TL074	Op-Amp, Quad, 14-pin DIP		DIP14 5		U102, U103, U104, U201, U206
100-1403-101 74HC595		8-bit Shift Reg. w/Output Latch	DIP16 4 U205, U207, U301, U302
100-1397-101 74HC7046		HIGH SPEED PLL w/LOCK DETECTOR	DIP16 1 U310
165-1387-102 MC68HRC908JK1P(20)		8-Bit Microcontroller	DIP-20	1	U200
100-1359-101	NE5532	Op-Amp, Dual, 8-pin DIP	DIP8	7	U5, U6, U100, U203, U204, U306, U309
100-1406-101	OPA-2134	Op-Amp, Dual, 8-pin DIP	DIP8	1	U7
100-1104-101	TL072	Op-Amp, Dual, 8-pin DIP	DIP8	1	U202
100-1333-103 THAT2181B VCA, Low-Noise, Low-THD			PAD-8	1	U105
REGULATOR/TRANSISTOR PARTS SECTION
100-1091-103 TIP112		NPN Transistor, Darlington - Small Signal	TO220-VERT	1	Q1
100-1089-101 uA7805		Voltage Regulator - 7800 Family	TO220-VREG	1	U4
100-1089-106 uA7812		Voltage Regulator - 7800 Family	TO220-VREG	1	U3
100-1042-102 uA7815		Voltage Regulator - 7800 Family	TO220-VREG	1	U2
100-1042-101 uA7915		Voltage Regulator - 7900 Family	TO220-VREG	1	U1
100-1181-101 2N4401	NPN Transistor - Single TO92-		EBC 14		Q3, Q4, Q5, Q6, Q7, Q8, Q9, Q10, Q11, Q100, Q104, Q300, Q301, Q308
100-1145-101 2N4403	PNP Transistor - Single TO92-		EBC 10		Q18, Q19, Q20, Q21, Q22, Q101, Q102, Q103, Q200, Q201
POT AND TRIMMER PARTS SECTION
165-1164-101 CTS ABS. ENCODER		CTS ABSOLUTE ENCODER	CTS ABS. ENCODER	1	SW204 sample rate
100-1010-101	25K	POT-TRIMMER	TRIMHORIZ	1	VR109 THD trim
100-1025-118 100K DUAL "C" TAPER		Pot, Dual Element	POT-9MM-DUAL	2	VR205 Mid-2 Freq, VR206 Mid-1 Freq
165-1027-105	5K DUAL/ 5%"C" TAPER	Pot, Dual Element	POT-16DUAL-H	1	VR2 Gain
165-1025-121 100K "A" TAPER		POT - Single Control / Trimmer	POT-9MM-SGL	1	VR103 Attack
100-1025-101	100K "B" TAPER	POT-TRIMMER	POT-9MM-SGL	1	VR102 Ratio
100-1025-103 10K "B"	TAPER POT-TRIMMER	POT-9MM-SGL 8			VR100 Expand/gate, VR105 Threshold, VR106 Output, VR108 De-Esser, VR200 Mid-2, VR202 High, VR203 Low, VR204 Mid-1
165-1025-115 5K "A"	TAPER"	POT - Single Control / Trimmer	POT-9MM-SGL 1	VR1 Impedance
164-1025-122 5K "C"	TAPER	POT - Single Control / Trimmer POT-9MM-SGL 2			VR104 Release, VR107 De-Esser Freq
CONNECTOR/JACK PARTS SECTION
100-5082-102 GP1FA550RZ Fiber optic reciever GP1FA550TZ 1 U317
100-5082-103	GP1FA550TZ	Fiber optic transmitter	GP1FA550TZ	1	U316
100-5291-101 XLR-PHONE COMBO		NEUTRIK XLR/PHONE COMBO JACK	XLR COMBO-HORZ	2	JK3 MIC/LINE INPUT, JK4 INPUT MIC/INST
100-5270-102 XLR-M-H		Switchcraft PD3MRML2 Male XLR right angle rear mount	XLR-M-H	2	JK201 OUTPUT, JK302 AES/EBU OUTPUT
100-5035-101 jack 1/4" washer gnd.		REFERENCE CLIFF CL14422	J-CLIF-GND	5	JK1 INSERT IN, JK2 MIC PRE OUTPUT, JK200 OUTPUT BALANCED, JK303 A/D CH2 INSERT, JK304 A/D MAIN INSERT
100-5225-102 J-CLIFF-GND		Jack, Cliff Stereo, with Grounding Clip	J-CLIF-GND	5	JK1, JK2, JK200, JK303, JK304
100-5262-101	TAB-FASTON		TAB.250	11	P1- P7, P201-P204
100-5080-101 BNC CONNECTOR		BNC-RAP2001 REFERENCE SWITCHCRAFT	BNC RT WITH WASHER AND NUT	2	JK300, JK301 WORDCLOCK
100-5081-101 RCA-041 SW JACK		90 degree switched RCA jack	RCA SW	1 JK305	S/PDIF
169-1001-101 USB CONNECTOR		Power Dynamics USB-FB1RPX1	JK306	1 JK306	USB
INDICATOR PARTS SECTION
LEDREPAIRKIT	LED Back light			1	M1
100-2005-107	VU METER W/tbox	NISSEI TN73 W/O BEZEL		1	M1
SWITCH PARTS SECTION
100-5022-104 SW-4PDT Switch, 4PDT, PCB Mount			SW-4PDT-FH-LIT2	2	SW101 EQ POSITION, SW202 LOW FREQ
100-5022-102 SW-DPT-FH Switch, DPDT, PCB mount			SW-DPDT-FH-LIT2	9	SW1, SW2, SW3, SW4, SW6, SW100, SW200, SW201, SW222 All other switches
165-2001-101	E-SWITCH P277-EE-1-C-X-C	E-SWITCH POWER SWITCH #P227-EE-2-C-X-C	SW-DPST-PWR 1	SW5 PWR SWT
MISC. PARTS
100-1200-101	12AX7A		TUBE-9PIN	1	V1
MECHANICAL PARTS SECTION
100-1511-101	TRANSFORMER, TOROID	20V-0-20V @.7A + 9V@.4A 120/240V PRIMARY		1	TR100 ( MAY REQUIRE FEMALE CONNECTORS)
ART Part #	Value Description		Footprint	Qty Location
100-5052-107 .75" KNOB /BLACK		TAIWAN KNOB 42006-2G-D (TKE) 2 VR2 GAIN, VR106 OUTPUT
100-5052-108 0.5" KNOB /BLACK		TAIWAN KNOB 42006-4G-D (TKE) 14			VR1, VR100, VR102, VR103, VR104, VR105, VR107, VR108, VR200, VR202, VR203, VR204, VR205, VR206, SW204
164-2004-101 LIT SWITCH CAP 12					SW1, SW2, SW3, SW4, SW5, SW6, SW100, SW101, SW200, SW201, SW202, SW222

FULL BILL OF MATERIALS

ART Part #	Value Description		Footprint	Qty	Location
AXIAL PARTS SECTION
100-1002-190 0 Ohm jumper		Resistor, Carbon Film,5% AXIAL0.4 1 R339
100-1002-176 1.5K		Resistor, Carbon Film,5% AXIAL0.4 4 R242, R243, R244, R245
100-1002-191 10 Ohms		Resistor, Carbon Film,5% AXIAL0.4 4 R29, R31, R32, R33
100-1002-103 100 Ohms		Resistor, Carbon Film,5%	AXIAL0.4 21		R69, R73, R163, R166, R254,R255, R256, R300, R308, R334,R180, R260-C269
100-1002-134 100K		Resistor, Carbon Film,5% AXIAL0.4 16			R43, R44, R45, R46, R49, R50,R71, R100, R104, R108, R110,R115, R118, R133, R275, R305
100-1002-117 10K		Resistor, Carbon Film,5% AXIAL0.4 44			R3-R17, R34, R36, R63, R70,R105, R106, R116, R117, R129,R132, R179, R200-R209, R231,R232, R233, R234, R235, R276,R277, R324
100-1001-401 10.0k Ohms		Resistor, Carbon Film,1% AXIAL0.4 2 R130, R131
100-1002-184 10M		Resistor, Carbon Film,5% AXIAL0.4 1 R147
100-1002-192 150 Ohms Resistor, Carbon		Film AXIAL0.4 12			R68, R127, R146, R155, R164,R169, R172, R175, R176, R177,R309, R314
100-1002-119 15K		Resistor, Carbon Film,5% AXIAL0.4 1 R320
100-1002-221 120K		Resistor, Carbon Film,5%	AXIAL0.4 1 R143
100-1002-177 160K		Resistor, Carbon Film,5% AXIAL0.4 1 R173
100-1002-106 1K		Resistor, Carbon Film,5% AXIAL0.4 10			R66, R120, R121, R122, R215,R222, R223, R224, R225,R270
100-1002-144 1M Resistor, Carbon Film AXIAL0.4 16					R55, R56, R57, R135, R140, R153,R154, R226, R227, R228, R229,R230, R310, R311, R312, R325
100-1002-216 33 Ohms		Resistor, Carbon Film,5%	AXIAL0.4 1 R30
100-1001-339 2.49K	Resistor, Carbon Film	AXIAL0.4 2 R51, R52
100-1002-109 2.4K		Resistor, Carbon Film,5% AXIAL0.4 4 R62, R344, R345, R346
100-1002-182 200K		Resistor, Carbon Film,5%	AXIAL0.4 1 R109
100-1002-122 20K		Resistor, Carbon Film,5% AXIAL0.4 7 R40-R42, R170, R174, R217, R304
100-1001-435 22.6K		Resistor, Carbon Film,5%	AXIAL0.4 2 R53, R54
100-1002-123 22K		Resistor, Carbon Film,5% AXIAL0.4 2 R240, R241
24 Ohms		Resistor, Carbon Film,5% AXIAL0.4 1 R67
100-1002-124 24K		Resistor, Carbon Film,5%	AXIAL0.4 1 R113
100-1002-104 200 Ohms		Resistor, Carbon Film,5%	AXIAL0.4 2 R18, R211
100-1002-181 240 Ohms		Resistor, Carbon Film,5%	AXIAL0.4 1 R144
100-1002197 270 Ohms		Resistor, Carbon Film,5% AXIAL0.4 2 R326, R329
100-1002-138 240K		Resistor, Carbon Film,5% AXIAL0.4 2 R60, R72
100-1002-153 2K		Resistor, Carbon Film,5%	AXIAL0.4 23		R1, R27, R28, R35, R37, R38,R112, R123, R125, R126, R162,R165, R168, R210, R212, R213,R214, R216, R246, R247, R271,R313, R342
27 Ohms, 1/2 W	AXIAL0.5 1 R273
100-1002-199 2.7K		Resistor, Carbon Film,5% AXIAL0.4 4 R236, R237, R238, R239
100-1002-112 3.9K		Resistor, Carbon Film,5% AXIAL0.4 1 R272
100-1002-159 300K		Resistor, Carbon Film,5% AXIAL0.4 4 R156, R157, R158
100-1002-169 330 Ohms		Resistor, Carbon Film,5%	AXIAL0.4 19		R11, R114, R119, R124, R128,R136, R137, R141, R142, R148,R181, R182, R183, R259, R306,R327, R330, R332
100-1002-127 33K		Resistor, Carbon Film,5% AXIAL0.4 3 R134, R145, R160
100-1002-128 39K		Resistor, Carbon Film,5%	AXIAL0.4 1 R151
100-1002-110 3K		Resistor, Carbon Film,5% AXIAL0.4 1 R315
100-1002-102 4.7 ohm		Resistor, Carbon Film,5% AXIAL0.4 1 R274
100-1002-113 4.7K		Resistor, Carbon Film,5% AXIAL0.4 3 R2, R103, R317
100-1001-368 4.99K		Resistor, Carbon Film,5%	AXIAL0.4 8		R58, R59, R61, R171, R218, R219,R220, R221
100-1002-179 47 Ohms		Resistor, Carbon Film,5% AXIAL0.4 2 R257, R258
100-1002-141 470K		Resistor, Carbon Film,5%	AXIAL0.4 4 R139, R150, R159, R161
100-1002-130 47K		Resistor, Carbon Film,5% AXIAL0.4 1 R252
100-1002-114 5.1K		Resistor, Carbon Film,5% AXIAL0.4 8			R102, R183, R301, R319, R322,R323, R328, R333
100-1002-185 5.1M		Resistor, Carbon Film,5% AXIAL0.4 2 R64, R65
ART Part #	Value	Description Footprint		Qty	Location
100-1002-187 510 Ohms		Resistor, Carbon Film,5% AXIAL0.4 18			R19, R20, R21, R22, R23, R24,R25, R26, R124, R302, R303,R309, R314, R316, R321 R340,R341, R343
100-1002-154 51K		Resistor, Carbon Film,5% AXIAL0.4 2 R152, R331
100-1002-115 6.8K		Resistor, Carbon Film,5% AXIAL0.4 2 R47, R48
100-1002-218 620 Ohms		Resistor, Carbon Film,5% AXIAL0.4 1 R337
100-1002-116 7.5K		Resistor, Carbon Film,5%	AXIAL0.4 1 R101
100-1002-213 75 Ohms		Resistor, Carbon Film,5% AXIAL0.4 3 R178, R180, R338
100-1001-485 75K		Resistor, Carbon Film,5%	AXIAL0.4 1 R149
	OPTIONAL PART DO NOT STUFF		2 R335, R336
100-1005-117 470pF		Resistor, Carbon Film,5% CAP-AXIAL 1 C217
100-1005-111 .001uF		Resistor, Carbon Film,5% CAP-AXIAL 1 C216
100-1001-401 10.0k Ohms		Resistor, Carbon Film,1% AXIAL0.4 4 R248-251
SMT RESISTORS
	1K Ohms		0603	2	R347, R348
	200 Ohms		0603	2	R349, R350
RADIAL PARTS SECTION
100-1035-103 .01uF	Capacitor, Film / Ceramic		RADIAL0.1 1	C47
100-1038-101 100pF	Capacitor, Film / Ceramic		RADIAL0.1	13	C28, C43, C107, C202, C203,C204, C205, C326, C327, C331,C332, C342, C343
100-1036-104	10pF monobloc	Capacitor	RADIAL0.1	3	C215, C220, C226
100-1036-102 150pF	Capacitor, Film / Ceramic		RADIAL0.1 1	C28, C34
100-1036-109 20pF	monobloc	Capacitor, Film / Ceramic	RADIAL0.1 3	C118, C348, C349
100-1036-101 330pF	Capacitor, Film / Ceramic		RADIAL0.1 6	C35, C38,	C39, C40, C52, C325
100-1036-103 33pF	Capacitor, Film / Ceramic		RADIAL0.1 5	C42, C44,	C46, C306, C307
100-1036-120 47pF	Capacitor, Film / Ceramic		RADIAL0.1 1	C300
	OPTIONAL PART DO NOT STUFF		RADIAL0.1 4	C334, C335
100-1037T116	.001uF	Capacitor, Film / Ceramic	RADIAL0.2
100-1037T103	.0033uF	Capacitor, Film / Ceramic	RADIAL0.2 3	C113, C117, C224
100-1037T102	.0047uF	Capacitor, Film / Ceramic	RADIAL0.2 1	C218
100-1037T106	.015uF	Capacitor, Film / Ceramic	RADIAL0.2 1	C225
100-1037T107	.022uF	Capacitor, Film / Ceramic	RADIAL0.2 3	C209, C323, C324
ART Part #	Value Description Footprint			Qty	Location
100-1037T111 .1uF	Capacitor, Film / Ceramic		RADIAL0.2 22		C41, C103, C104, C105, C106,C206, R223, C308, C310, C311,C312, C313, C315, C316, C317,C318, C319, C320, C321, C322,R336, R337
100-1009T109 .22uF	Capacitor, Film / Ceramic		RADIAL0.2 2 C207, C208
ELECTROLYTIC CAPACITOR PARTS SECTION
100-1162-115	.15uF	Capacitor, Electrolytic(polarized)	LYTIC.1	3 C37	C328, C329
100-1008-101	.47uF 50V	Capacitor, Electrolytic(polarized)	LYTIC.1	4 C110	C111, C221, C222
100-1008-102	1uF/50V	Capacitor, Electrolytic(polarized)	LYTIC.1	9	C109, C114, C219, C228, C302,C338, C339, C340, C341
100-1162T114 220u	F/6.3V	Capacitor, Electrolytic(polarized)	LYTIC.1	9	C29, C30, C31, C32, C33, C200,C201, C346, C347
100-1162T117 22uF	35V	Capacitor, Electrolytic(polarized)	LYTIC.1	33	C4, C5, C6, C7, C8, C9, C10, C11,C36, C49, C50, C51, C100, C101,C102, C115, C116, C210, C211,C212, C213, C214, C227, C230,C309, C333, C344, C345, C350
	4.7uF	Capacitor, Electrolytic(polarized)	LYTIC.1	1 C47
100-1162-109	47uF	Capacitor, Electrolytic(polarized)	LYTIC.1	1 C301
100-1162-124	100uF/100V	Capacitor, Electrolytic(polarized)	LYTIC.2	9	C12, C13, C14, C15, C16, C17,C18, C19, C20
100-1162-125	100uF/200V	Capacitor, Electrolytic(polarized)	LYTIC.2	3 C21	C22, C23
100-1162-107	2200uF/16V	Capacitor, Electrolytic(polarized)	LYTIC.2	3 C24	C25, C48
100-1162-112	2200uF/35V	Capacitor, Electrolytic(polarized)	LYTIC.2	3 C1,	C2, C3
100-1162-110	470uF/25V	Capacitor, Electrolytic(polarized)	LYTIC.2	3 C26	C27, C229
	OPTIONAL PARTS	DO NOT STUFF			C334, C335
DIODE PARTS SECTION
100-1029T101 1N41	48	Diode - Signal or PowerRectifier	DIODE0.4	26	D13, D14, D18, D19, D100, D101,D102, D103, D104, D105, D106,D107, D108, D109, D110, D111,D112, D115, D118, D200, D202,D203, D205, D300, D301, D304
100-1030-102	1N5235B	Diode, Zener, <= 1w	DIODE0.4	1	D114
100-1030-101	1N5231B	Diode, Zener, <= 1w	DIODE0.4	3	D116,D119, D121
100-1030-107 1N5240B Diode, Zener, <=	1w DIODE0.4 1 D113
100-1030-101 1N5261B Diode, Zener, <=	1w DIODE0.4 1 D15
100-1030-108 1N5818 1N5818 shottkey diode DIODE0.4 3 D120, D201, D204
100-1098-101 1N4003	Diode - Signal or Power Rectifier	DIODE0.4LG 15		D1, D2, D3, D4, D5, D6, D7, D8, D9, D10, D11, D12, D16, D17, D22, D23, D24
IC PARTS SECTION
100-1134-101 LM339AN QUAD COMPARATOR DIP14 5 U106, U107, U108, U109, U110
100-1271-101 TL074	Op-Amp, Quad, 14-pin DIP	DIP14 5 U102, U103, U104, U201, U206
100-1403-101 74HC595	8-bit Shift Reg. w/Output Latch	DIP16 4 U205, U207, U301, U302
100-1397-101 74HC7046	HIGH SPEED PLL w/LOCK DETECTOR	DIP16 1 U310
165-1387-102 MC68HRC908JK1P(20)	8-Bit Microcontroller	DIP-20	1	U200
100-1359-101 NE5532 Op-Amp, Dual, 8-pin DIP		DIP8	7	U5, U6, U100, U203, U204, U306, U309
100-1406-101 OPA-2134 Op-Amp, Dual, 8-pin DIP		DIP8	1	U7
100-1104-101 TL072 Op-Amp, Dual, 8-pin DIP		DIP8	1	U202
100-1333-103 THAT2181B	VCA, Low-Noise, Low-THD	PAD-8	1	U105
SMT PARTS SECTION
100-1348-101 LM3046M	Transistor Array, 3-NPN + 1-Diff Pair NPN	SO-14	1	U101
100-1116-103 74HC00	Quad 2-IN Nand Gate	SO-14	1	U300
100-1398-101 74HC74	Flip-Flop, Dual D-Type w/Preset & Clear	SO-14	1	U305
100-1399-101 74HC161	Synchronous 4-Bit Binary Counter	SO-16	2	U303, U304
100-1404-101 74HC4053	Analog Switch, 3PDT - 3 Control Lines	SO-16	2	U307, U308
100-1401-101 AL-1401A	ALESIS OPTICAL OUTPUT GENERATOR	SOL-20	1	U315
100-1402-101 AL-1402	ALESIS OPTICAL INPUT RECIEVER	SOL-24	1	U313
100-1410-101 PCM-1804	24 bit, 192KHz A/D converter	SSOP-28	1	U314
100-1409-101 DIT-4192	192KHz Digital audio transmitter	TSSOP-28	1	U318
165-2001-101 XF5756-ER9	XFMRMS - 192KHz AES/EBU TRANSFORMER	XF5756-ER9	1	TR300
	PCM2902 USB INTERFACE I.C.		1	U311
REGULATOR/TRANSISTOR PARTS SECTION
ART Part #	Value Description Footprint			Qty	Location
100-1091-103 TIP112	2	NPN Transistor, Darlington - Small Signal	TO220-VERT 1 Q1
100-1134-105	LM317T(3)	3-TERMINAL ADJUSTABLE REGULATOR AND 3-AMP ADJUSTABLE REGULATOR TO220-VREG 1 U8
100-1089-101 uA7805		Voltage Regulator - 7800 Family TO220-VREG 1 U4
100-1089-106 uA7812		Voltage Regulator - 7800 Family TO220-VREG 1 U3
100-1042-102 uA7815		Voltage Regulator - 7800 Family	TO220-VREG 1 U2
100-1042-101 uA7915		Voltage Regulator - 7900 Family TO220-VREG 1 U1
100-1181-101 2N4401	NPN Transistor - Single TO92-EBC 14				Q3, Q4, Q5, Q6, Q7, Q8, Q9, Q10, Q11, Q100, Q104, Q300, Q301, Q308
100-1145-101 2N4403	PNP Transistor - Single TO92-EBC 10				Q18, Q19, Q20, Q21, Q22, Q101, Q102, Q103, Q200, Q201
100-1144-103 2SA1316		PNP - high gain,low noise/80V	TO92-ECB	2 Q16, Q17
100-1098T103	BF423	PNP Transistor - Single	TO92-ECB	4	Q12, Q13, Q14, Q15
POT AND TRIMMER PARTS SECTION
100-1164-101	CTS ABS. ENCODER	CTS ABSOLUTE ENCODER	CTS ABS. ENCODER	1 SW204
100-1010-101	25K	POT-TRIMMER	TRIMHORZ	1	VR109
100-1025-105	100K DUAL "C" TAPER	Pot, Dual Element	POT-9MM-DUAL	2 VR205, VR206
100-1025-120	5K DUAL/ 5%"C" TAPER	Pot, Dual Element	POT-16DUAL-H	1	VR2
100-1025-121 100K	"A" TAPER	POT - Single Control / Trimmer	POT-9MM-SGL	1 VR103
100-1025-101	100K "B" TAPER	POT-TRIMMER	POT-9MM-SGL	1	VR102
100-1025-103	10K "B" TAPER	POT-TRIMMER	POT-9MM-SGL	8	VR100, VR105, VR106, VR108, VR200, VR202, VR203, VR204
165-1025-115 5K "A" TAPER		POT - Single Control / Trimmer	POT-9MM-SGL	1 VR1
164-1025-122 5K "C" TAPER		POT - Single Control / Trimmer	POT-9MM-SGL	2 VR104, VR107
CONNECTOR/JACK PARTS SECTION
100-5082-102	GP1FA550RZ	Fiber optic reciever	GP1FA550TZ	1	U317
100-5082-103	GP1FA550TZ	Fiber optic transmitter	GP1FA550TZ	1	U316
100-5291-101	XLR-PHONE COMBO	NEUTRIK XLR/PHONE COMBO JACK	XLR COMBO-HORZ	2 JK3, JK4
100-5270-102 XLR-M-H		Switchcraft PD3MRML2 Male XLR right angle rear mount	XLR-M-H	2 JK201, JK302
ART Part #	Value	Description	Footprint	Qty	Location
100-5035-101 jack 1	/4" washer gnd.	REFERENCE CLIFFCL14422 J-CLIF-GND 5	JK1, JK2, JK200,	JK303, JK304
100-5225-102 J-CLIFF-GND		Jack, Cliff Stereo, with Grounding Clip J-CLIF-GND 5	JK1, JK2, JK200,	JK303, JK304
100-5262-101 TAB-FASTON TAB.250		1 P1-P7, P201-P204
100-5080-101 BNC CONNECTOR		BNC-RAP2001REFERENCE SWITCHCRAFT	BNC RT WITH WASHER AND NUT 2 JK300,	JK301
100-5081-101 RCA-041 SW JACK		90 degree switched RCA jack RCA SW	1 JK305
100-1138-310 FLEX-10		10 WIDE FLEX STRIP,ONE END DEPICTED	SIP-10	10	JP1, JP200, JP300, JP700, JP702,JP800, JP802, JP900, JP902, JP906
100-1138-305 FLEX-5		FLEX STRIP-FIVE WIDE	SIP-5	6	JP310, JP704, JP804, JP806,JP904, JP908
169-1001-101 USB CONNECTOR		Power Dynamics USB-FB1RPX1	JK306	1 JK306
INDICATOR PARTS SECTION
100-1136-103 Red	Kingbright-WP1043ID		Kingbright-WP1043ID	2	LED300, LED301
	RED BARGRAPH	MV57164 REDBARGRAPH		2 U111, U112
	GREEN BARGRAPH	MV54164 GREENBARGRAPH		1 U113
	RED,YELLOW,GREEN	MV5A164 RED,YELLOW, GREENBARGRAPH		1 U114
100-1136-104	Yellow	Kingbright-WP1043YD	LED-L383	1 LED	103
100-1132-102 Blue		LED - Single, T1, T1 3/4,T1 plus SMD 1205 SIZE,W/LENS - KINGBRIGHTAPTD3216PBC (BLUE)	LED-T1	2 LED2, LED222
100-1031-119 Orange		LED - Single, T1, T1 3/4,T1 plus SMD 1205 SIZE,W/LENS - KINGBRIGHTAPTD3216PBC (BLUE)	LED-T1	9	LED1, LED3, LED4, LED6, LED100,LED101, LED200, LED201, LED202
100-1031-122 Red		LED - Single, T1, T1 3/4,T1 plus SMD 1205 SIZE,W/LENS - KINGBRIGHTAPTD3216PBC (BLUE)	LED-T1	1 LED5
100-2005-107 VU METER W/box		NISSEI TN73 W/OBEZEL		1 M1
SWITCH PARTS SECTION
100-5022-104 SW-4PDT		Switch, 4PDT, PCBMount	SW-4PDT-FH-LIT2	2 SW	101, SW202
100-5022-102 SW-DPDT-FH		Switch, DPDT, PCBmount	SW-DPDT-FH-LIT2	9	SW1, SW2, SW3, SW4, SW6,SW100, SW200, SW201, SW222
165-2001-101	E-SWITCH P277-EE-1-C-X-C	E-SWITCH POWERSWITCH #P227-EE-2-C-X-C	SW-DPST-PWR	1 SW5
MISC. PARTS
ART Part #	Value Description Footprint			Qty	Location
100-1158T101 100u	H Inductor, Iron Core	CHOKE0.2 1 L401
100-1200-101 12AX	7A TUBE-9PIN 1 V1
100-1222-246 10.84	8MHz	Crystal - Series or Par. Mode	XTAL-HC18 1 X300
100-1222-246 12.00	0MHz	Crystal - Series or Par. Mode XTAL-HC18 1 X301
100-1228-103 RELA	Y-DPDT, 12V HS212	12	RELAY-DPDT-DIP	2 RL1, RL300
100-5068-101 TUBE	SOCKET	Tube, Dual Triode (9-pin mini)	TUBE-9PIN 1 V1
100-5204-106	HEATSINK #100-5204-106	Heatsink, Add-On to TO-220	HTSK-5204-106 5	HS1, HS2, HS3, HS4, HS5
MECHANICAL PARTS SECTION
165-3001-103	PCB BOARD			1
100-5216-104	.250" x .203" "L" bracket	Keystone #543-621	BRKT-90^-FRT	4	Gain display, Output display
100-1511-101	TRANSFORMER, TOROID	20V-0-20V @.7A + 9V@.4A 120/240V PRIMARY		1	TR100 ( MAY REQUIRE FEMALE CONNECTORS)
100-5027-122 6/32-3	3/8 ROLOX	9			POWER INLET, GND LUG,COVER, PCB-PCB STANDOFF
	STANDOFF, PCB-PCB, 1.2", THREADED FOR 4-40 SCREWS	2
	Tube Shield/Spring/Collar	1 V1
	4-4-40x 1/8" screws			10	V1, Gain Display, Output display
	2-.350"#4 threaded standoffs	2 V1
	4-40 X 1/4" Pan head black, phillips	12	PCB to PCB standoffs, "L" brackets
100-5030-106	NUT 6-32 HEX NYLOK	3 POWER INLET, GND LUG
	#4BX3/8 PH PN HD ST BLK SCREW	16			CHASSIS TO FRONT, JK3,JK201,JK302,U316,U317 (OPTICAL JACKS), LED PCB MOUNTING
100-5032-131	SCREW 4-40X1/4 FLAT HEAD UNDER CUT	PCB TO STANDOFF		2 SCREWS FOR JK4
100-5033-113	1/4 JACK PLASTIC NUT	REAR PANEL		6 JK1,JK2,JK100,JK200,JK303,JK304
ART Part #	Value	Description	Footprint	Qty	Location
100-5052-107 .75" K	NOB /BLACK	TAIWAN KNOB 42006-2G-D (TKE) 2 VR2, VR106
100-5052-108 0.5" K	NOB /BLACK	TAIWAN KNOB 42006-4G-D (TKE) 14			VR1, VR100, VR102, VR103, VR104, VR105, VR107, VR108, VR200, VR202, VR203, VR204, VR205, VR206, SW204
159-2009-200	POWER INLET IEC w/FUSE W/ VOLTAGE SELECT	REAR PANEL 1 PL100
165-2001-200 FRONT PANEL 1
165-2002-200 CHASSIS 1
165-2003-200 COVER 1
165-2004-200 Window 2.600		X .650 1 Atten. Window
165-2005-200 Window 2.600		X .650 1 Level Window
215-8002-100	HARNESS .187 TO GND LUG	1 HARNESS .187 TO GND LUG, 6"
255-8002-101	HARNESS PRIMARY AC	1
165-2002-101 LIT SWITCH CAP 12					SW1, SW2, SW3, SW4, SW5, SW6, SW100, SW101, SW200, SW201, SW202, SW222
	#8 1 1/2" SCREW	FOR TRANSFORMER		1	TR100
	#8 WASHER	FOR TRANSFORMER		1	TR100
	#8 NYLOK NUT	FOR TRANSFORMER		1	TR100
	.125" ADHESIVE BASE STANDOFF	PCB TO CHASSIS	2
PACKAGING PARTS
500-5011-100 PKG BAG 1		15.75(OPEN)x26.500".002
165-	PKG BOX	1 MTL UNIT BOX
100-6003-101 SERIAL LABEL 2
-	END CAPS	2 PKG MTL ENS CAP
000-100-120	WARRANTY CARD	1
000-100-121	WARRANTY ENVELOPE	1
165-5004-101 MANUAL 1		PKG MANUAL
MFG 9169-101	BAG	1			PKG BAG 6"X6" X .002 FOR MANUAL PACKAGE
100-1057-109	110V IEC POWER CORD	1

WARRANTY INFORMATION

Limited Warranty (USA only)

Applied Research and Technology will provide warranty and service for this unit in accordance with the following warrants:

Applied Research and Technology, (A R T) warrants to the original purchaser that this product and the components thereof will be free from defects in workmanship and materials for a period of three years from the date of purchase. Applied Research and Technology will, without charge, repair or replace, at its option, defective product or component parts upon prepaid delivery to the factory service department or authorized service center, accompanied by proof of purchase date in the form of a valid sales receipt.

Online Registration

Please go to www.artproaudio.com. Select "Support", then "Product Registration" input your information here.

Exclusions

This warranty does not apply in the event of misuse or abuse of the product or as a result of unauthorized alterations or repairs. This warranty is void if the serial number is altered, defaced, or removed.

A R T reserves the right to make changes in design or make additions to or improvements upon this product without any obligation to install the same on products previously manufactured.

A R T shall not be liable for any consequential damages, including without limitation damages resulting from loss of use. Some states do not allow limitations of incidental or consequential damages, so the above limitation or exclusion may not apply to you. This warranty gives you specific rights and you may have other rights, which vary from state to state.

For units purchased outside the United States, an authorized distributor of Applied Research and Technology will provide service.

SERVICE

The following information is provided in the unlikely event that your unit requires service.

1. Be sure that the unit is the cause of the problem. Check to make sure the unit has power, all cables are connected correctly, and the cables themselves are in working condition. You may want to consult with your dealer for assistance in troubleshooting or testing your particular configuration.
2. If you believe that the ART unit is at fault, go to www.artproaudio.com. Select "Support", then "Return Authorization Request" to request a return authorization number.
3. If you are returning the unit for service, pack the unit in its original carton or a reasonable substitute. The original packaging may not be suitable as a shipping carton, so consider putting the packaged unit in another box for shipping. Print the RA number clearly on the outside of the shipping box. Print your return shipping address on the outside of the box.
4. Include, with your unit, a note with the RA number and your contact information, including a return shipping address (we cannot ship to a P.O. box) and a daytime phone number, and a description of the problem, preferably attached to the top of the unit. Also include a copy of your purchase receipt.

Please fill in the following information for your reference:

Date of purchase: ____

Purchased from: ____

Serial Number: ____

SPECIFICATIONS

Input Impedance

Mic 150 to 3.4K Ohms, variable

Line....20K Ohms

Instrument....2.5M Ohms

Preamp Insert....7.5K Ohms

A/D Inserts 10K Ohms

Output Impedance

Balanced Outputs....200 Ohms balanced

Preamp Output....100 Ohms

A/D Inserts 510 Ohms

Frequency Response

Analog In to Analog Out 12 Hz to 100 KHz +0, -1 dB

Analog In to Digital Out....12 Hz to 20 KHz +0, -1 dB @ 44.1 KHz sample rate

16 Hz to 42 KHz +0, -1 dB @ 96 KHz sample rate

THD

1 KHz ....≤ .015% typical

20 to 20 KHz ....≤ .033% typical

Equivalent Input Noise

Mic/Line....-130 dBu, Input shorted, Max gain, "A" weighted

Instrument....-105 dBu, Input shorted, Max gain, "A" weighted

Maximum Input Level

Mic/Line....+18 dBu balanced with PAD

Instrument....+15 dBu

Maximum Gain

Mic 70 dB (XLR to balanced output)

Instrument 40 dB (1/4-inch to balanced output)

Maximum Output level

Balanced....+20 dBu

Unbalanced....+20 dBu

Output Level At Meter 0 VU ....+4 dBu

Preamp

Microphone Gain....0 dB to +60 dB

Instrument Gain....+3 dB to +40 dB

Low Cut Filter 100 Hz, 1-pole, 6 dB/Octave

EQ

Boost/Cut ....±12 dB on each band

Low Freq. Tuning ....50/150 Hz Selectable

MID 1 Freq. Tuning....100 Hz to 3 KHz continuously variable

MID 2 Freq. Tuning....500 Hz to 15 KHz continuously variable

High Freq. Tuning....5K/15 KHz Selectable

Compressor/Limiter

Attack Time 250 uSec. to 100 mSec.

Release Time....100 mSec to 3 Sec.

De-esser Tuning....2.5 KHz to 15 KHz continuously variable

Compression Ratio....1:1 to 20:1

Expander Slope....1:1.5

Digital section

Wordclock Range....30 KHz to 204 KHz

Sample Rates....44.1 KHz, 48 KHz, 88.2 KHz, 96 KHz, 176 KHz, 192 KHz

A/D Dynamic Range....106 dB "A" weighted

USB A/D Dynamic Range....94 dB "A" weighted

Dimensions (HWD) 3.50-inch x 19.0-inch x 9.17-inch, 88.9mm x 483mm x 233mm

Weight....10.5 lbs., 4.76kg

Power Requirements....USA – 105 to 125 VAC/ 60 Hz Export units configured for country of destination.

USB Minimum System Requirements....USB Class compliant plug-and-play Mac and PC interface

Note: 0 dBu = 0.775 VRMS, 0 dBV = 1 VRMS

ART maintains a policy of constant product improvement. ART reserves the right to make changes in design, or make additions to, or improvements upon, this product without any obligation to install same on products previously manufactured. Therefore, specifications are subject to change without notice.

APPLIED RESEARCH AND TECHNOLOGY

www.artproaudio.com

E-mail: [e-mail]

© 2020 Applied Research & Technology

Voice Channel

165-5004-107

Tube Channel Strip with Digital Connectivity