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 donÂŽt 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 itÂŽs 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:âą 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.âą Line input impedance: 10K Ohms bridging, Carnhill transformer balanced and floating.âą DI input impedance: Greater than 2 Megohms, unbalanced.âą Output impedance: Less than 75 Ohms, Carnhill transformer balanced and floating, to drive a load of 600 ohms (factory terminated).âą Maximum output: Greater than +26dBm into 600 ohms.âą THD: Less than 0.025% at 1 Khz, less than 0.05% at 100Hz.âą Frequency response: 20Hz ( +0.3dB ) to 20Khz (-0.2dB)âą Maximum gain: Slightly greater than 80dBâą Noise: Less than -100dBm.âą Power consumption: Less than 200 mA @24VDC