Drum Machine with Teensy 4.1

Drum machines come in a variety of quality/feature levels and price points. If you want something truly unique, with a low price tag (plus whatever your time is worth) you can always build something like Albert Nyström's excellent $70 device. It's based on the Teensy 4.1, and looks and sounds quite interesting as it cranks out beats in the video below.

An explanation of what it’s actually doing starts at around the 3:35 mark in the clip, noting that it has three voices, each with a trio of knobs to modify frequency, decay, and tone, as well as a switch to flip between one of three voice types. A number of common-use knobs to modify characteristics such as volume, high/low-pass filtering, randomness, and more. There's even an overdrive/distortion knob to really crank things up as needed.

More technical insight into the internals is seen via pictures starting at the 9:00 mark. In addition to the Teensy 4.1, it employs a UDA1334 DAC; perfboards and wires for connection; and an array of potentiometers, buttons, and switches as the user interface.

One curious bit seen in the video is when Nyström pushes LEDs to make changes. While one might guess its a capacitive setup, he actually situated small buttons below these lights to allow for this action. If you’d like to create your own – or something similar – more info is found on the drum machine’s GitHub page.