The UglyFace is a DIY guitar synthesizer/fuzz circuit designed by Tim Escobedo. The fuzz is a gated square-wave with with splattery note decay; and octave-down/subharmonic effects for nasal, tearing synth tones. It is intentionally unstable and primitive-sounding. Chords usually become chaotic; single-note riffs, slides, harmonics and volume-knob swells tend to work better.

This PCB is from Pedal Freaks in Japan. They make lots of great kits that you may have seen branded as Samurai Sound/Takky Parts or on a trip to Akihabara, Tokyo.

The Ugly Face became a DIY classic because it is relatively simple, inexpensive and highly interactive. It also invites modification: blend controls, oscillator-range switches, LFOs, expression inputs and alternate frequency capacitors are common additions. Add a Pedal Freaks Blend Mixer kit (sold separately) to mix the LM386 fuzz signal with the oscillator output, retaining more recognizable guitar attack.

Translated Japanese instructions included. No exotic parts needed!!!