A Midas-transformer preamp for your 500 series rack.
You track vocals and instruments, and a slot in your 500 series rack is waiting. The 73 is a microphone preamplifier with custom-built Midas transformers and discrete Class-A amplifiers. Its inputs and output are transformer balanced. Frequency response is 20 Hz to 20 kHz, ±0.5 dB.
Coarse steps, then fine trim
A rotary GAIN switch moves in 5 dB steps. The microphone range is -20 dB to -80 dB, and the line range is -20 dB to +10 dB. TRIM then adds -20 dB to +5 dB, with a centre detent at unity gain.
Front panel or rack input
Press FR I/P to use the front XLR/¼" TRS combi socket instead of the rack input. LO Z selects a low microphone input impedance, 300 Ω instead of 1200 Ω. It operates on the mic input only.
Phantom power and phase at a touch
Press the TRIM knob to switch 48 V phantom power on or off, in the mic range only. PHASE reverses the phase of the output signal. The SIG LED lights green above -25 dBu and red near overload, above +26 dBu.
