Description
The Heritage Audio DMA73 is high quality re-creation of the microphone preamp section of the venerable 1073.
The unit includes settings for Mic, Line or DI input. The microphone input utilizes a Carnhill transformer and can either be set to 1200 Ohm (HI) or 300 Ohm (LO) minimum. Higher gain positions gradually have greater impedances, optimum for lo gain ribbon mics.
An international voltage external supply is included.
The combination of wood and RAF blue grey steel makes the tabletop units aesthetically stand out in any professional recording environment and will bring your semi pro facility the touch of class you´re looking for.
Features
- 80dB Class A Microphone preamplifier, HI-LO selectable minimum input impedance, balanced and floating. High gain positions show a higher impedance, ideal for old ribbon mics.
- 50Db Class A Line preamplifier, bridging input impedance, balanced and floating.
- All discrete Class A Ultra High Impedance J-Fet Direct Input on a high quality Neutrik Jack. The DI circuit is ahead of the Mic Input transformer, so the transformer is on when in DI mode.
- Class A single ended, 2N3055 driven, high headroom output stage.
- Individual Neutrik gold plated XLR connectors for microphone and line inputs.
- Gold Plated Neutrik XLR output.
- PAD: 20dB Mic input attenuation ahead of the input transformer to avoid overloading it.
- HI PASS FILTER: Active all discrete Class A 3rd order Bessel, 80Hz Hi Pass Filter. 18dB/octave slope.
- OUTPUT control to allow overloading of the preamp.
- External linear PSU to avoid electromagnetic radiation into the audio transformers ( a.k.a. hum ).
- Carnhill Input and Output transformers.
- 3 gain stage, genuine B283 gain card modular construction.
- Marconi style knobs and vintage style engraved pushbutton
Specifications
Microphone input impedance: HI, 1200 Ohm minimum, LO, 300 Ohm minimum. Higher gain positions gradually have greater impedances, optimum for lo gain ribbon mics. Input is Carnhill transformer balanced and floating.
Line input impedance: 10K Ohms bridging, Carnhill transformer balanced and floating.
DI input impedance: Greater than 2 Megohms, unbalanced.
Output impedance: Less than 75 Ohms, Carnhill transformer balanced and floating, to drive a load of 600 ohms (factory terminated).
Maximum output: Greater than +26dBm into 600 ohms.
THD: Less than 0.025% at 1 Khz, less than 0.05% at 100Hz.
Frequency response: 20Hz ( +0.3dB ) to 20Khz (-0.2dB)
Maximum gain: Slightly greater than 80dB
Noise: Less than -100dBm.
Power consumption: Less than 200 mA @24VDC
