Sub page: 16 chan audio mixer
design 1990

Description: I designed and build this because I could not find one, needing many stereo line inputs only and flexible output routing.

This one has 16 stereo input channels, 6 stereo outputs (A-B-C-D-E-F). Each channel has a levelpot, a panpot and a pot for a a common effect send (mono). Each channel can be switched to the main output (A) or to one of the other 5 outputs that could be connected to effect processors. Each channel input has a gainswitch L-M-H on the backpanel with 10dB steps to normalise amplitudes ( see circuit drawing link at the bottom of this page).
The 32 input preamps (16x2) are directly mounted on the input connectors to minimise wiring crosstalk. No PCBs were designed only perfboard and standard DIL adapter boards were used.
The unit runs on an external +/12V power supply to prevent hum pickup from the transformer.

Front:

Back:

Inside:

Inside zoom on preamps:

circuit diagram: schematics