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.

Wednesday, August 10, 2016

Hungry Robot Mosfet Screamer

About a month or so ago, Hungry Robot Pedals made a limited run of overdrives called the Mosfet Screamer. As the name implies, it's based of the classic Ibanez Tube Screamer, but with a fair amount of modification. Eric from Hungry Robot was kind enough to share the schematic on Instagram, so a big thanks to him. Here's what he had to say about it:

The Mosfet Screamer strips the input and output buffers and adds a pre-gain Mosfet Gain stage to make it a bit more beefy. One thing I wanted was a more usable tone control, so I did some value changes and added a treble bleed on the volume section. Standard Gain, Tone, Volume controls and two toggles switches (One to select between two clipping options and the other to adjust the gain of the Mosfet Stage from low to high).


  1. Thanks to your layout this pedal will no longer be a limited edition! There may be an error between the pinout of the clip switch on both schemes?

    1. It'll function the same way. Just a typo on my part.

  2. Verified. Cool take on a tube screamer.

  3. What is "Q" or transistor for using this layout ?