This is loosely based on TeensyPoly6's schematic, but with many changes of various significance:
- It uses a Teensy 4.1, as the 3.5 wasn't available when this was designed (and is now discontinued).
- It takes the form of a single 2-layer PCB with all pots, switches, and buttons directly affixed. I suppose you could run wires to a front panel if you really wanted to.
- It leans much more heavily into the multiplexers, with 8 instead of 1. This results in a more efficient use of pins.
- It adds a few more controls and enables full ADSR envelopes on the amp and filter.
- It adds LEDs to indicate system state (and greatly aid debugging).
- It adds a rotary dial to select the desired MIDI channel.
