This is a library of perfboard and single-sided PCB effect layouts for guitar and bass. I'm not an electrical engineer by any stretch of the imagination, just a DIY'er who likes drawing layouts. It is meant for the hobbyist (so commercial use of any of these layout is not allowed without permission) and as a way to give back to the online DIY community.

Friday, August 14, 2015

Escobedo Ugly Face

Today's #fuzzfriday is an Tim Escobedo design: the Ugly Face. Here's what he had to say about it:

The Uglyface is a completely all-out fuzz unit for fat, noisy buzzsaw sounds. P1 sets the threshold for triggering the fuzz. This characteristic also means that notes can fade out abruptly when they decay below the set level. P2 is the frequency control. It functions as an unorthodox tone control, at one extreme producing synthesized octave down effects, at the other extreme, thin and nasal tones. When the threshold is set below the trigger point, the Uglyface becomes a free running oscillator, with P2 controlling the frequency. P3 is a Sensitivity control, regulating how much of the guitar signal will modulate the Frequency control.

Make sure the second IC is a CMOS 555 otherwise the effect won't work. Here's the schematic for reference.


  1. I've built a couple Ugly Faces with great results. The first I shelled out the $ for the vactrol, but the second I made a basic LDR/LED in heatshrink and it worked just fine.

    I love this pedal. I'm planning to build one inside of a strat and call it the "Uglycaster"!

    1. cool! so your use this layout and work fine? excuse my bad english

    2. Oh man... I'm a little late with catching this question!

      Yes. This layout worked for me. Verified.

      However, I've since completed an Ugly Face with LFO in a vero layout and I like that one better. Not just because of the LFO, but because I have more range in the other controls before it hits self-oscillation. I'd have to go back and look to see if there were any real differences in component values.