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.

Tuesday, January 6, 2015

Vox Repeat Percussion Tremolo

This cool little effect was originally housed in a small box that plugged directly into your amp (which you then plugged your guitar into) and later on some of Vox's higher end guitars. You'll need to track down an obsolete 2N2646 unijunction transistor for Q1, but they can be found on eBay or Small Bear. It produces a thumpy sounding tremolo that could be really useful if you're trying to cover The Who's "Baba O'Riley" and need to do the intro on guitar.

Here's the stock version:

And with an added depth control:


  1. Just built mine with all vintage metal can transistors from small bear, on etched pcb, with the depth control mod.

    Freakin' love it. Thanks!

  2. Sounds awesome! This will be my first clone.

  3. Hello everyone!!. Would anyone know how to add a pulsing LED to this tremolo (with depth control mod)? Something like Colorsound Tremolo which I did but did not work because the sound came out clean, with no effect at all. I tried several things but I gave up. Thanks for any reply.