Just published the Ugly Face v 1.1 to OSH Park. Built and tested, it works well! This is classic DIY project, it’s almost a rite of passage for new DIY stomp box enthusiasts.
The Ugly Face is more of a synthesizer than fuzz pedal. It produces square output from the input guitar signal. You can imagine the internal oscillator running whenever the input signal reaches a threshold. This gives you frequencies above or below the input frequency at the output. The Ugly Face also adds an envelope control to animate the oscillator frequency. The sound is surprisingly more musical than a lot of other “harsh” distortions.
Order some boards at OSH Park and follow the build docs below to make your own.