Here's another Seppuku FX fuzz box. The sound is kind of in the vein of Devi Ever or Death by Audio. The texture control pans between thick overdrive and over the top fuzz. This one should fit in a 1590a. I included a daughter board for the pots to cut down on some off board wiring.
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.