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Halo Distortion / Sustainer

Based On
EHX® Big Muff Pi
Effect Type
Distortion / Sustainer, Fuzz
Build Difficulty
Project Summary
One of the most classic guitar effects of all time, its sound falls somewhere between a distortion effect and a fuzz with an incredibly long sustain.

Complete Kit

What's included?
Everything you need to build the full pedal except for the tools.


Out of stock

Currently unavailable, but we expect to have more soon. Sign up for the mailing list to be notified of restocks and new products.
Halo Distortion / Sustainer printed circuit board

PCB Only

What's included?
Just the PCB, build instructions and parts list. You order the parts and take it from there.


In stock

Project overview

The Halo Distortion/Sustainer is a recreation of the Electro-Harmonix Big Muff Pi, first released in 1969. Originally marketed as a “harmonic distortion sustain”, it has been lumped together with fuzz effects, although it’s a very different animal than classic fuzz effects like a Fuzz Face or a Tone Bender.

The Big Muff is something of a “rite of passage” for pedalbuilders. It’s a pretty easy build and there aren’t a lot of things that can be messed up. There’s no biasing or gain sorting, and no rare or specialized parts are needed. It’s endlessly tweakable, with dozens of different variants (some of which sound very different) that are just a matter of substituting a few parts.

The Big Muff circuit was adapted by a number of other pedal manufacturers in the 1970s. Notably, the 4th version of the Colorsound Tone Bender, called the Supa Tone Bender and released in 1973, was based on the Big Muff circuit. The next version of the Tone Bender, called the Jumbo Tone Bender and released in 1976, changed the standard Big Muff circuit by removing the 4th transistor, a make-up gain stage after the tone control. This 3-transistor variant was copied by other manufacturers as well.

Demo Video

Check out RJ Ronquillo’s demo video of the Halo Distortion / Sustainer.
Watch on YouTube →