Going to the BK Synth and Pedal Expo with Tardio last weekend, reminded me about how neat they are. A few resources for DIY guitar pedal building…

Preliminary thoughts

In a way, there are only about 6 different types of guitar pedals. Yet, there is tremendous variety in the offerings, most differentiated by microdifferences, user interface, and branding/packaging. Make of that what you will.

Background reading: Pedal Crush seems great, but is no longer in print.

Analog Circuits

Alan Lanterman’s Guitar Amplification and Effects course (previously mentioned among his other music-EECS courses).
Electrosmash has some nice analysis of classic pedals
(20 July 2025) Guitarpedalcourse.com offers an online course on pedal circuit design. Looks a bit pricey, but interesting, particularly if you pair it with a Labor kit to facilitate prototyping the audio circuits.

DSP

As much as I want to love analog, we live in the digital age.

Open-source DSP pedal kit based on the daisy seed
(26 mar 2025) Raspberry-Pi Pico multi-effect pedal — very low part count, well explained. Has some very interesting links including to musicDSP “a collection of algorithms, thoughts and snippets, gathered for the music dsp community”
(12 apr 2025) Yet another Raspberry-Pi pico guitar pedal design. It appears to use a DAC for audio output (maybe better than doing PWM as in the previous one, but doesn’t seem as well documented )
(24 Jan 2026) The Polyend Endless is a user-programmable DSP pedal…they are also including a “vibecoding” mode for defining effects by LLM. Discussion at HackerNews
- (12 Feb 2026) Folks appear to be doing open-source VST plugin design through vibecoding (e.g., APC), so it doesn’t seem like much of a lift to adapt that to devices like these.

Parerga and paralipomena

(25 Sept 2025) From a certain point of view, chorus pedals can be thought of as microtonal shimmer chords