Heritage Audio DTT-73 2-Channel Class A Portable Mic-Line Preamp User Manual

: June 9, 2024
: Heritage Audio

Table of Contents

DTT-73 2-Channel Class A Portable Mic-Line Preamp
- DTT-73
- INTRODUCTION
- DESCRIPTION
- REAR
- APPLICATIONS
- MIC
- D.I.
- APPLICATIONS
- D.I. & AMP
- LINE
- SPECIFICATIONS
- SIGNAL FLOW
- WARRANTY STATEMENT
- REGISTRATION
- RECALL SHEETS
- References
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DTT-73 2-Channel Class A Portable Mic-Line Preamp

DTT-73

2-CHANNEL CLASS A PORTABLE
MIC/LINE PREAMP WITH D.I.
TABLE TOP

USER MANUAL
August/2022 Rev. 1.0.

INTRODUCTION

Thank you for choosing the Table top DTT-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.

DESCRIPTION

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

Standing for DTT- 73, it is in essence a reformatted single channel DMA 73 with a very sturdy construction for portable use in any environment. The DTT-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.

portable mic GETTING STARTED

INPUT GAIN SWITCH 5dB Steps From 30 to 80
THRU OUTPUT To also send D.I. signal to Amp, simultaneously
THRU GND LIFT Disconnects the ground pin from the connector
D.I. Switch to activate the D.I. Input
PHANTOM POWER Activates 48 V
HIGH PASS FILTER -3 dB at 82 Hz, Discrete Class A
OUTPUT ATTENUATOR Attenuates from 0 to Infinity
D.I. INPUT High Impedance Class A JFET
MIC INPUT IMPEDANCE 1200 Ω or 300 Ω when pressed
LINE Switches from MIC/D.I. to Line
MIC PAD 20 dB Reduction Ahead of Input Transformer
PHASE Flips phase 180º
+24 V LIGHT Lights to confirm proper internal voltage in available
+48 V LiGHT Lights to confirm proper voltage for PHANTOM POWER is available

REAR

POWER INPUT
To Be Connected to a standard
IEC cable for powering
ON/OFF
Switch to activate unit
LINE OUTPUT
Male XLR Connector
LINE INPUT
Female XLR Connector
MIC INPUT
Female XLR Connector

All XLRs are:

P in 1: GND
Pin 2: Hot
Pin 3: Cold

D.I. Jack:

Tip: Signal
Sleeve: Ground

APPLICATIONS

MIC

mic

D.I.

xlr connection

APPLICATIONS

D.I. & AMP

amp

LINE

SPECIFICATIONS

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): 275 mm x 135 mm x 240 mm.
Weight: 4,342 Kg.

SIGNAL FLOW

|
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TROUBLE SHOOTING| 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 DTT-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 to the DTT-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 DTT-73 input.

There is a ground like noise on my amp.|

Try pushing the ´LIFT´ button to see if it helps.

WARRANTY STATEMENT

LIMITED 2 YEAR WARRANTY

Heritage Audio DTT-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.