Just a Teensy 3.1 Arduino development board turned synth.
Thanks for your interest in my "Teensy" Synth. Here's a video that covers all of the features I included on the synthesizer.
The directory above contains a schematic diagram, a feature list/cc&channel guide pdf, and the .ino file which contains the code, as well as a parts list and some wiring instructions to supplement the schematic.
Below are two videos showing 5 of these synthesizers making music.