The POLY555 is a polyphonic, analog, square wave synth based on the 555 timer chip.

• Polyphonic:​ Multiple notes can be played simultaneously. This is opposed to "monophonic," where only one note at a time can be played.
• Analog:​ There are no computers, microcontrollers, sound samplers, or anything digital involved. The sound you hear is the sound of a speaker being abused by discrete electronic components like capacitors and resistors and logic chips.
• Square-wave:​ When its output is viewed on an oscilloscope, its wave resembles a square. It’s a “hard” sounding wave type, commonly associated with chiptune music and old video games

These are the 3D models for the POLY555 Synth DIY Kit from Oskitone.

Assembly Guide

Find a detailed assembly guide with printing and soldering instructions at
https://oskitone.github.io/poly555/

Updates

January 23, 2021: Added reduced_test_case
November 2, 2021: Chamfer headlocking cavity on trimpot_knob