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.
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.