The Big Muff may be a classic distortion design, but it is often too much of a good thing. The cascaded gain stages with the dual diode clipping will remove most of the dynamic range from the sound. This article is about trimming down the basic design to give back some of the dynamics, enhance transparency and make the pedal a more useful and versatile distortion/overdrive.
When I was designing the pcb for the Multi-Fuzz, which uses mosfet, germanium and silicon transistors, it occurred to me that I could build a simplified Big Muff on the same pcb, if I made a few additions to it. Since this has always been a project that I wanted to try, I made those changes and the mini-muff version was born.
It turned out to be a great project with some nice low gain overdrive sounds. It is perfect for adding just a bit of crunch to fatten up a guitar tone. The full schematic is available online for you to build on perfboard or stripboard, but you can order the Mini-Muff pcb to make construction easier.
Get the full schematic and parts list for this transistor overdrive.
Here is the prototype of the mini-muff pedal that I installed in an pedalbox that I recycled from an old project, which is why it has the Cheesetone decal on it.
I usually power this pedal with my standard AC power supply sent through a V-Doubler converter which provides a stable positive ground 9v supply needed for this circuit. (see image below)
I have also powered it with my rechargeable battery pack through the V-Doubler, and that works just as well.