10/15/2026
Portable DIY Teensy Synth Anyone?
Four-voice polyphony, drum samples, built-in speakers, and a 3.5mm output jack, all running on a Teensy 4.1 inside a hard case you can carry with one hand.
We teamed up with Jeremy Cook to build a portable DIY synthesizer from arcade buttons, a Teensy Audio Shield, and a Qwiic Speaker Amp. Thirteen arcade buttons give you a full C3-to-C4 keyboard with sharps and flats, two more shift octaves up or down, and four trigger drum samples. The whole system handles four notes simultaneously, so chords actually work.
The real fun is in the design decisions. Jeremy wired every button through spade connectors and screw terminals so the main board lifts right out for modifications. USB battery power keeps it portable, and the audio path splits between internal speakers and an external jack for plugging into bigger systems or recording.
The full tutorial walks through the schematic, 3D-printed supports, wiring, and the Teensy Audio library code. The link is in the first comment if you want to build your own (or adapt it into something completely different).
Learn how to make your own at https://hubs.ly/Q04Blp0L0