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.

Monday, September 28, 2015

Mad Professor Sky Blue Overdrive

Here's another BJF designed circuit: the Sky Blue Overdrive. There are 4 controls: Z adjusts input impedance, Distort. controls gain, Texture adjusts the hard clipping, and finally the Volume. It uses 3mm LEDs in the feedback loop of the opamp, and then JFETs for hard clipping.


  1. what is the best substitute for OP275?

  2. Try some dual opamps like the TL072 or NE5532. Also Google is your friend

  3. volume 2 to out, dist 3 left unconnected?

  4. using NE5332, works
    u can mark it verified
    thank you David