This 2 channels audio mixer is based on the 2n3904 transistors which forms 2 pre-amplifiers. The first preamplifier of the audio mixer has a high gain and can be used for microphone input, and the ...

its Transistor Mixer, a four-channel utility mixer for Eurorack modular synthesizers. They say that, at 6HP width, the new module is suitable for both audio and control voltage processing. Its ...