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.