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, November 28, 2016

MXR Distortion III

Here's the MXR Distortion III. It's pretty similar to the MXR ZW-44, which itself is a Boss SD-2 clone. The main difference is hard clipping in the Distortion III instead of soft clipping in the ZW-44/SD-2. Originals use an MC33178P dual opamp, but try a JRC4558 or TL072.


  1. Hello,

    I found one mistake on the PCB. Clipping diodes must go to 4,5V, not to ground.


  2. Verified. Quite low output volume though. a bit below unity when on full volume. I Don't know if that's normal?

    1. I don't think that's normal. You might want to troubleshoot that a bit.

    2. Thanks, I'll see what I can find with a probe

  3. Just made it. Couldn't find MPSA14, so MPSA13 was used, IC is 4558.
    After turning on there is very loud and continous squeeeeeak, and guitar sounds like from fuzz.
    Any ideas?