MIDI Controlled Dual Stereo Audio Switch/Mixer
Updated: Apr 29
Commissioned build. Switches two sets of stereo pathways to a set of outputs according to MIDI program change commands. Like a supercharged dual A/B/Y switch.
Based on Arduino and 8 reed relays, the signal path is all analog, and mixing (A AND B) is accomplished with op-amp summing amplifiers.
Opto-isolated MIDI In, software THRU. A WS2812b-based RGB LED for state indication. USB port on the side is purely for programming, and is mounted with a custom designed and 3d printed bracket. Takes 12VDC in.
Update April 2021
4 Units were built up for testing, Elliot Freedman built a fantastic web utility to edit parameters over sysex using Chrome's Web MIDI functionality. Because configuration is done over sysex, an exposed USB port is no longer needed.