Homemade Polyphonic Synth

Synthesizers can play a variety of sounds, typically using a piano-style user interface. From there, synthesizers and electronic music go off in countless directions, allowing one to produce a limitless number of tones and melodies. One fundamental characteristic of a synth is whether it’s monophonic – e.g. can play one tone at a time – or polyphonic, capable of playing multiple tones simultaneously.

Naturally, polyphonic synths are preferable in the vast majority of situations, and the more notes that can be played at once – the number of synth voices – help determine a device's capability. As demonstrated in the video below, Albert Nyström created his own six-voice polyphonic synth, using a Teensy 3.5 plus a handful of other components for control, and an old M-Audio Keystation 49 as the interface and body of the device.

The video starts out with a demo of Nyström playing the instrument, with captions that explain what’s going on starting at around the 5:00 mark. It’s quite the interesting performance, showing off the device’s capabilities, including three oscillators, and a really fun looking pitch-bend wheel.

Code for the device can be found here, along with a schematic. While Nyström claims – perhaps unfairly – that the schematic is ugly, the component count is pretty low, so it should be possible to duplicate. Whether or not you would want to build something similar, it looks and sounds fantastic.