This set of PCBs allows you to build a vintage 312-type microphone preamplifier.
Here are the key features of our 312 module:
- Very short signal path. Switching via relays.
- Active FET DI circuit.
- Switchable -20 dB input pad.
- Switchable low impedance input.
- Switchable additional output transformer winding for increased output level.
- Optional servo circuit mod.
- Optional 3124+ type mod (caps on the output of the op-amp).
- Includes our take on the 2520 discrete op-amp.
These PCBs are intended to be used in our 4-channel frame system. 312 module takes up one slot space and needs +/-22V or higher (unregulated) for proper operation. We suggest installing no more than two modules if using internal PSU.