Heritage Audio DMA73

Dual mic preamp

The Heritage Audio DMA73 is a true dual 1073 style mic preamp in a 1 rack unit format. It has some added key features that will cover all the recording needs for engineers and musicians that don´t find the need to track with eq.

Employing only discrete circuitry and conventional components, the DMA73 is a faithful 3 stage all class A 1073 preamp. Styroflex and tantalum capacitors have been used throughout. No corners cut.

A useful all discrete class A hi pass filter has been added, essential for recording everything with the exception of probably kick drum and and bass.

The Line mode allows for reamping of prerecorded tracks and it´s perfect for adding some class A color to lifeless recordings.

The DI circuit is an all discrete class A JFET circuit ahead of the MIC transformer, so all the juice is there. Since its introduction in 2012, it has become a classic DI for bass.

Power handling has been addressed by means of an external linear power supply, which is included in the package.

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: 88 mA per rail @+-16VDC.