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Zelus Distortion / Sustainer

Based On
Blackout® Musket Fuzz
Effect Type
Distortion / Sustainer, Fuzz
Build Difficulty
Project Summary
Based on the classic Big Muff circuit, this pedal adds a boost to drive the input, a bass blend capacitor, and a midrange control inside the tone stack.
Zelus Distortion / Sustainer printed circuit board

Printed Circuit Board

What's included?
PCB only. Build instructions and parts list can be viewed or downloaded from this page.


In stock

Complete Kit

Not yet available.
Kits are developed based on interest, so if you’d like to see one for this project, let us know.
Request Kit
20 people are interested.

Project overview

The Zelus Distortion/Sustainer is adapted from the Blackout Effectors Musket Fuzz version 2, a Big Muff-based circuit with a few modifications.

First, an input boost has been added to the front of the circuit. This boost is adapted from the Electro-Harmonix LPB-1 and allows you to drive the input harder than the initial gain stage in a stock Big Muff.

Second, a “Focus” control has been added to blend in a higher capacitor value and allow more bass through before the clipping stages. With this feature, the Musket is great for bass guitar.

Third, a “Midrange” control has been added to the treble side of the rotation allowing another capacitor to be gradually blended in parallel with the stock tone capacitor, changing the frequency of that side. Note that if the tone control is turned all the way to the bass side (counter-clockwise), the Midrange control will have almost no effect.

With these enhancements, the Musket is a unique and modern take on the Big Muff while retaining the character of the vintage circuit.