Mitxela has continued a project to make the “smallest and worst” synthesizers possible – and he’s one-upped himself this time. This MIDI synth is barely larger than the size of its USB-C connector.

Heck this is smaller the size of the caps on some early synths. It’s tiny. Really tiny. Really useless and silly and tiny. Just watch:

This is an iteration of an attempt to be as small as possible in a kind of conceptual design effort – last time, it was a MIDI connector, a piezo buzzer, and a Teensy. Now, USB-C enables an even smaller design. In the “smallest and worst,” “no one is competing with me.” (Be careful, though; those designs are open-source, so I can think of one maker who… never mind.)

There are a lot of clever features here, meaning that this design might even inspire some more, uh, practical ones that are not a choking hazard:

  • Ultra-cheap, 32-bit CH32V003 RISC-V microcontroller
  • USB stack, which he found just before attempting to make one himself –
  • USB MIDI working (as proof of concept)
  • Bespoke USB dev board
  • Lush, velvety monophonic square wave sound! (Listen to the beautiful resonance that USB-C hub produces – eat your heart out, ghost of Antonio Stradivari!)

And it does make sound. Full build description:

Smallest USB-C MIDI Synth

Source code:


Why not. Why not indeed.

Thanks to Artemiy for this one, and I expect we’ll be putting two of these in our coffee instead of sugar, right?