I’ve designed an open source (hardware and software) eight-loop switcher. It fits in a 1590D enclosure (just) and uses dual-coil relays for quiet switching. There’s a small screen to manage presets, and it can send downstream MIDI (no MIDI in, though, at least not in this revision). The brains of the operation is an Arduino Nano Every, which controls the relays and LEDs.
Demo:
Source code and hardware: https://github.com/optilude/LoopSwitcher
Demo:
Source code and hardware: https://github.com/optilude/LoopSwitcher