TT-73 - Audio/video converter Heritage Audio - Free user manual and instructions

Product Type	Microphone Preamplifier (500 Series Module)
Brand	Heritage Audio
Model	TT-73
Dimensions (Width x Depth x Height)	1.5 x 7 x 5.25 inches (38.1 x 177.8 x 133.35 mm)
Weight	1.5 lbs (0.68 kg)
Power Supply	+24V DC via 500 series rack edge connector; phantom power +48V from rack
Input Impedance	1200 ohms (mic), 10 kohms (line), 1 Mohm (instrument)
Output Impedance	75 ohms
Maximum Gain	80 dB (mic) / 20 dB (line) / 40 dB (instrument)
Frequency Response	20 Hz – 20 kHz ±0.5 dB
Equivalent Input Noise (EIN)	-120 dBu (150 ohm source)
Maximum Output Level	+26 dBu into 600 ohms
Input Connections	XLR (mic/line) + 1/4" TS (instrument) via rear module
Output Connections	XLR via rear module
Special Features	Class-A 1073-style transformer-balanced preamp; Carnhill transformers; variable gain with stepped switches; –20 dB pad; phase reverse; 48V phantom; line/instrument switch
Maintenance	Clean with a dry, lint-free cloth. Do not use solvents or abrasive cleaners. Keep ventilation slots free of dust.
Safety	Do not expose to rain or moisture. Disconnect from power before cleaning. No user-serviceable parts inside.
Spare Parts & Repairability	Contact Heritage Audio or authorized service centers for spare parts and repairs. Only qualified technicians should open the module.
General Information	500 series format, compatible with standard lunchbox racks. Includes screws for mounting. Made in Spain.

Frequently Asked Questions - TT-73 Heritage Audio

What is the Heritage Audio TT-73?

The Heritage Audio TT-73 is a 500-series microphone preamplifier inspired by the classic 1073 console preamp. It features a class-A topology with Carnhill transformers for a vintage tone.

How do I install the TT-73 in a lunchbox rack?

Slide the module into an empty 500-series slot, ensuring the edge connector aligns. Secure it with the included screws. Connect input and output via the rear module XLR connectors.

Does the TT-73 have an equalizer?

No, the TT-73 is a pure microphone preamplifier without EQ. It focuses on transparent gain with a classic character.

What is the gain range of the TT-73?

The gain ranges from 20 dB to 80 dB (mic), selectable via stepped switches in 5 dB increments. Line and instrument gain ranges are different.

Can I use the TT-73 with ribbon microphones?

Yes, but ensure phantom power is turned off for most ribbon mics. The TT-73 has a –20 dB pad and phase reverse to aid compatibility.

Does the TT-73 require phantom power?

It does not generate phantom power itself; it passes +48V from the rack when enabled via the front switch. You need a rack that provides phantom power.

What is the maximum output level of the TT-73?

The maximum output level is +26 dBu into 600 ohms, ensuring compatibility with professional gear.

How do I clean the TT-73?

Use a dry, lint-free cloth to wipe the front panel. Avoid liquids and compressed air. Do not spray cleaners directly on the module.

Is the TT-73 compatible with all 500-series racks?

Yes, it follows the 500-series standard. It works in any standard lunchbox rack such as Heritage Audio, API, or others that supply ±16V and +48V.

What is the warranty for the TT-73?

Heritage Audio offers a limited lifetime warranty to the original purchaser. Register your product online for full coverage. Contact support for details.

USER MANUAL TT-73 Heritage Audio

1-CHANNEL CLASS A PORTABLE

MIC/LINE PREAMP WITH D.I.

TABLE TOP

USER MANUAL

Thank you for choosing the Table top TT-73. Heritage Audio is dedicated to bringing you 'the sound of yesterday for tomorrow'. We specialize in capturing that unique, enticing sound that everybody has fallen in love with. For years engineers, producers and musicians have been yearning for that classic vibe. Usually the only option is to search for old, used original equipment that is almost always in a questionable state of operation. This brings with it a whole lot of other issues, making the experience less than desirable. Not to mention the very high prices asked for this equipment, which makes them virtually unobtainable for the great majority. Now it's possible to obtain that same sound with a brand new piece that will give you all the problem-free, heavy-duty use you'll need for years of music making history.

Peter Rodriguez

CEO

Heritage Audio - Madrid, Spain

© 2022 Heritage Audio S.L. is the sole owner of the copyright of all information and drawings contained in this manual which are not to be copied or reproduced by any means or disclosed in part or whole to any third party without written permission.

Heritage Audio reserves the right to alter specifications without notice. The information in this manual has been carefully checked and is believed to be accurate at the time of publication. However, no responsibility is taken by us for inaccuracies, errors or omissions nor any liability assumed for any loss or damage resulting either directly or indirectly from use of the information contained within it.

TABLE OF CONTENTS

INTRODUCTION	2
CONTENTS	2
DESCRIPTION	3
GETTING STARTED	4
APPLICATIONS	5
SPECIFICATIONS	6
SIGNAL FLOW	6
TROUBLE SHOOTING	7
WARRANTY STATEMENT	8
REGISTRATION	8
RECALL SHEETS	9

One Channel Class A Portable Mic/LinePreamp with D.I.

Standing for TABLETOP 73, it is in essence a reformatted single channel DMA 73 with a very sturdy construction for portable use in any environment. The TT-73 widens the range of applications to on-stage use, portable systems, hotel rooms, on-site location recordings, etc. It even has its own handle to make lugging it around as easy as can be.

Now musicians are able to give 73-driven line levels to FOH engineers, using the front panel DI inputs. While on the road they are able to record at the same studio quality level from hotel rooms, etc. Stage microphones can be brought up to line level without using long cable runs. These are just some of the possibilities.

Special care has been taken with the internal worldwide power supply, which has been custom engineered to operate close to audio transformers with no noise induced.

New to the range of tabletop units is the implementation of DI THRU jacks for simultaneous use of instrument amplifiers. A ground lift switch prevents any ground loops from introducing hum into the audio signal.

The combination of wood and RAF blue gray steel makes the tabletop units aesthetically stand out in any professional recording environment and will bring your pro or semi pro facility the touch of class your customers are looking for.

Also worth mentioning is the DTT-73. It is a 2 channel version, exactly the same but with twice the power. Instead of just a single channel, it's a 'double' TABLETOP 73. A very attractive option for those that need two inputs simultaneously.

FRONT

1	2	3	4	5
INPUT GAIN SWITCH5 dB Steps From 30 to 80	THRU OUTPUTTo also send D.I. signal to Amp, simultaneously	THRU GND LIFTDisconnects the ground pin from the connector	D.I.Switch to activate the D.I. Input	PHANTOM POWERActivates 48 V
6	7	8	9	10
HIGH PASS FILTER-3 dB at 82 Hz, Discrete Class A	OUTPUT ATTENUATORAttenuates from 0 to Infinity	D.I. INPUTHigh Impedance Class A JFET	MIC INPUT IMPEDANCE1200 Ω or 300 Ω when pressed	LINESwitches from MIC/D.I. to Line
11	12	13	14
MIC PAD20 dB Reduction Ahead of Input Transformer	PHASEFlips phase 180°	+24 V LIGHTLights to confirm proper internal voltage in available	+48 V LiIGHTLights to confirm proper voltage for PHANTOM POWER is available

REAR

1	2	3	4	5
POWER INPUTTo Be Connected to a standard IEC cable for powering	ON/OFFSwitch to activate unit	LINE OUTPUTMale XLR Connector	LINE INPUTFemale XLR Connector	MIC INPUTFemale XLR Connector

All XLRs are:

Pin 1: GND

Pin 2: Hot

Pin 3: Cold

MALE XLR

FEMALE XLR

D.I. Jack:

Tip: Signal

Sleeve: Ground

Sleeve Sleeve=Ground/Shield

graph TD
    A["CONDenser MIC"] --> B["TT-73 TABLETOP MIC AMPLIFIER"]
    B --> C["USB - COMPUTER"]
    C --> D["Line INPUT - AUDIO INTERFACE"]
    D --> E["Output"]
    E --> F["Line INPUT - Audio Interface"]
    F --> G["MIC INPUT"]
    G --> H["Activated +48 V FOR CONDENSER"]
    H --> I["MT200 MHz"]
    I --> J["Output"]
    J --> K["Line INPUT - Audio Interface"]
    K --> L["Output"]
    L --> M["Line INPUT - Audio Interface"]
    M --> N["Output"]

graph TD
    A["Input - Bass AMP"] --> B["Heitage Audio"]
    B --> C["TT-73 TABLETOP MIC AMPLIFIER"]
    C --> D["D.I. INPUT"]
    D --> E["Line Input - Audio Interface"]
    E --> F["USB - COMPUTER"]
    F --> G["Output"]
    G --> H["Line Input - Audio Interface"]
    H --> I["Output"]
    I --> J["Line Input - Line 1.0"]
    J --> K["Line Input - Line 2.0"]
    K --> L["Line Input - Line 3.0"]
    L --> M["Line Input - Line 4.0"]
    M --> N["Line Input - Line 5.0"]
    N --> O["Line Input - Line 6.0"]
    O --> P["Line Input - Line 7.0"]
    P --> Q["Line Input - Line 8.0"]
    Q --> R["Line Input - Line 9.0"]
    R --> S["Line Input - Line 10.0"]
    S --> T["Line Input - Line 11.0"]
    T --> U["Line Input - Line 12.0"]
    U --> V["Line Input - Line 13.0"]
    V --> W["Line Input - Line 14.0"]
    W --> X["Line Input - Line 15.0"]
    X --> Y["Line Input - Line 16.0"]
    Y --> Z["Line Input - Line 17.0"]
    Z --> AA["Line Input - Line 18.0"]
    AA --> AB["Line Input - Line 19.0"]
    AB --> AC["Line Input - Line 20.0"]
    AC --> AD["Line Input - Line 21.0"]
    AD --> AE["Line Input - Line 22.0"]
    AE --> AF["Line Input - Line 23.0"]
    AF --> AG["Line Input - Line 24.0"]
    AG --> AH["Line Input - Line 25.0"]
    AH --> AI["Line Input - Line 26.0"]
    AI --> AJ["Line Input - Line 27.0"]
    AJ --> AK["Line Input - Line 28.0"]
    AK --> AL["Line Input - Line 29.0"]
    AL --> AM["Line Input - Line 30.0"]
    AM --> AN["Line Input - Line 31.0"]
    AN --> AO["Line Input - Line 32.0"]
    AO --> AP["Line Input - Line 33.0"]
    AP --> AQ["Line Input - Line 34.0"]
    AQ --> AR["Line Input - Line 35.0"]
    AR --> AS["Line Input - Line 36.0"]
    AS --> AT["Line Input - Line 37.0"]
    AT --> AU["Line Input - Line 38.0"]
    AU --> AV["Line Input - Line 39.0"]
    AV --> AW["Line Input - Line 40.0"]
    AW --> AX["Line Input - Line 41.0"]
    AX --> AY["Line Input - Line 42.0"]
    AY --> AZ["Line Input - Line 43.0"]
    AZ --> BA["Line Input - Line 44.0"]
    BA --> BB["Line Input - Line 45.0"]
    BB --> BC["Line Input - Line 46.0"]
    BC --> BD["Line Input - Line 47.0"]
    BD --> BE["Line Input - Line 48.0"]
    BE --> BF["Line Input - Line 49.0"]
    BF --> BG["Line Input - Line 50.0"]
    BG --> BH["Line Input - Line 51.0"]
    BH --> BI["Line Input - Line 52.0"]
    BI --> BJ["Line Input - Line 53.0"]
    BJ --> BK["Line Input - Line 54.0"]
    BK --> BL["Line Input - Line 55.0"]
    BL --> BM["Line Input - Line 56.0"]
    BM --> BN["Line Input - Line 57.0"]
    BN --> BO["Line Input - Line 58.0"]
    BO --> BP["Line Input - Line 59.0"]
    BP --> BQ["Line Input - Line 60.0"]
    BQ --> BR["Line Input - Line 61.0"]
    BR --> BS["Line Input - Line 62.0"]
    BS --> BT["Line Input - Line 63.0"]
    BT --> BU["Line Input - Line 64.0"]
    BU --> BV["Line Input - Line 65.0"]
    BV --> BW["Line Input - Line 66.0"]
    BW --> BX["Line Input - Line 67.0"]
    BX --> BY["Line Input - Line 68.0"]
    BY --> BZ["Line Input - Line 69.0"]
    BZ --> CA["Line Input - Line 70.0"]
    CA --> CB["Line Input - Line 71.0"]
    CB --> CC["Line Input - Line 72.0"]
    CC --> CD["Line Input - Line 73.0"]
    CD --> CE["Line Input - Line 74.0"]
    CE --> CF["Line Input - Line 75.0"]
    CF --> CG["Line Input - Line 76.0"]
    CG --> CH["Line Input - Line 77.0"]
    CH --> CI["Line Input - Line 78.0"]
    CI --> CJ["Line Input - Line 79.0"]
    CJ --> CK["Line Input - Line 80.0"]

graph TD
    A["LINE INPUT- AUDIO INTERFACE"] --> B["USB - COMPUTER"]
    B --> C["Line INPUT - TA TELLA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVID A/DVI OUTPUT<br>    A --> D[Line OUTPUT - KEYBOARD"]
    D --> E["Line OUTPUT - TA TELLA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVI OUTPUT<br>    A --> F[Line OUTPUT - TA TELLA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVID A/DVI OUTPUT<br>    A --> G[Line OUTPUT - TA TELLA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVID A/DVI OUTPUT<br>    A --> H[Line OUTPUT - TA TELLA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVID A/DVI OUTPUT<br>    A --> I[Line OUTPUT - TA TELLA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA/DAVIDA 0"]
    D --> J["Line OUTPUT - TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA"]
    E --> K["Line OUTPUT - TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / SAUTATION"]
    F --> L["Line OUTPUT - TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TNATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATATAT ATTT-73"]
    G --> H["Line OUTPUT - TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TOV-100"]
    H --> I["Line OUTPUT - TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TOV-100"]
    I --> J["Line OUTPUT - TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TOV-100"]
    J --> K["Line OUTPUT - TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TOV-100"]
    K --> L["Line OUTPUT - TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TOV-100"]
    L --> M["Line OUTPUT - TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TOV-100"]
    M --> N["Line OUTPUT - TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TOV-100"]
    N --> O["Line OUTPUT - TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TOV-100"]
    O --> P["Line OUTPUT - TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TOV-100"]
    P --> Q["Line OUTPUT - TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TOV-100"]
    Q --> R["Line OUTPUT - TA TELLA / TA TELLA / TA TELLA / TA TELLA / TA TELLA / TOV-100"]
    R --> S["Line OUTPUT - TA TELLA / TA TELLA / TA TELLSO"]
    S --> U["Line OUTPUT - HAID/AUDIC"]
    U --> V["Line OUTPUT - HAID/AUDIC"]
    V --> W["Line OUTPUT - HAID/AUDIC"]
    W --> X["Line OUTPUT - HAID/AUDIC"]
    X --> Y["Line OUTPUT - HAID/AUDIC"]
    Y --> Z["Line OUTPUT - HAID/AUDIC"]
    Z --> AA["Line OUTPUT - HAID/AUDIC"]
    AA --> AB["Line OUTPUT - HAID/AUDIC"]
    AB --> AC["Line OUTPUT - HAID/AUDIC"]
    AC --> AD["Line OUTPUT - HAID/AUDIC"]
    AD --> AE["Line OUTPUT - HAID/AUDIC"]

• Microphone input impedance: High=1200 Ω minimum; Low=300 Ω minimum. Higher gain positions gradually have greater impedances, optimum for low gain ribbon mics. Input is transformer balanced and floating.
• Line input impedance: 10 kΩ bridging, transformer balanced and floating.
• Output impedance: Less than 75 Ω, transformer balanced and floating, to drive a load of 600 Ω.
  • D.I. input impedance: Greater than 2 MΩ, unbalanced.
  • Maximum output: Greater than +26,5 dBu into 600 Ω (internally terminated).
• THD: Less than 0,025 % at 1 kHz, Less than 0,05 % at 100 Hz.
  • Frequency response: 20 Hz (+0,3 dB) to 20 kHz (-0,2 dB).
  • Maximum Gain: Slightly greater than 80 dB.
  • Power supply: Internal no-noise PSU, accepting worldwide voltages from 100 V to 240 V.
• Dimensions (W x H x L): 238 mm x 95 mm x 250 mm.
  • Weight: 3,020 Kg.

SIGNAL FLOW

graph TD
    A["MIC/LINE INPUT"] --> B["CARNHILL TRANSFORMER"]
    C["D.I."] --> B
    B --> D["INPUT AMP"]
    D --> E["HIGH PASS FILTER"]
    E --> F["OUTPUT AMP"]
    F --> G["LINE OUTPUT"]
    H["PHASE"] --> G
    I["LOZ"] --> B
    J["LIFT"] --> K["THRU"]
    L["PAD"] --> B

Abstract black-and-white graphic of a human head silhouette with a question mark and a small 'H' symbol below (no text or symbols present)

Illustration of a glowing incandescent light bulb with a stylized 'H' symbol on its side (no text or labels)

PROBLEMS	SOLUTIONS
There doesn’t appear to be any signal at all arriving at the back input XLR.	Make sure the GAIN knob is not in the ‘Off’ position.
There still doesn’t appear to be any signal at all arriving at the back input XLR.	Check to see if a jack cable has been left plugged into the front panel D.I.
Even at the lowest position on the GAIN knob I still have too much gain.	When this happens you should activate the PAD button. This will reduce the input by 20 dB ahead of the input transformer.
Condenser microphones don’t seem to work with TT-73.	Make sure the red +48 V button is pressed in to activate the phantom power sent to the microphone.
There doesn’t seem to be any output at all from the unit.	Check to see if the OUTPUT knob is fully turned down as this will attenuate the signal completely.
Sending a signal to the unit from a DAW overloads it terrible.	It is necessary to press the LINE button when sending it a line level source. If not, it is expecting a Microphone signal with a very different impedance.
I’d like to use my amp but have connected my guitar the TT-73 to send to the FOH engineer.	Simply tap the signal from the THRU output jack. It is identical to the signal received at the TT-73 input.
There is a ground like noise on my amp.	Try pushing the ‘LIFT’ button to see if it helps.

* For any further doubts or questions please get in contact with us at: [e-mail]

LIMITED 2 YEAR WARRANTY

Heritage Audio TT-73 is warranted by Heritage Audio SL to be free from defects in materials and workmanship for the period of 2 years to the original purchaser. In the event of such defects, the product will be repaired without charge or, at our option, replaced with a new one if delivered to Heritage Audio prepaid, together with a copy of the sales slip or other proof of purchase date. The warranty excludes problems due to normal wear, abuse, shipping damage or failure to use the product in accordance with the specifications.

Heritage Audio shall not be liable for damages based upon inconvenience, loss of use of the product, loss of time, interrupted operation or commercial loss or any other damages, whether incidental, consequential or otherwise.

This warranty is not transferable.

Heritage Audio and the Heritage Audio "H" logos are registered Trademarks owned and/or licensed by Heritage Audio.

REGISTRATION

Please visit our website: https://heritageaudio.net/registration/

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www.heritageaudio.com

HERITAGE AUDIO. C/ Alfonso Gómez, 38, 3C. 28037 Madrid – Spain. Tel: [phone]

[e-mail]