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Helios (Legacy)

Based On
Pro Co® RAT Distortion
Effect Type
Build Difficulty
Project Summary
A distortion pedal with a very distinctive and tight mid-to-high-gain character that made it a staple in the rigs of 1980s hard rock bands.

Legacy PCB

Designed for the 1590B enclosure with side-mounted jacks, which some builders prefer. Bypass PCB (optional) sold separately.


In stock

Updated Version

The same circuit, but updated for the 125B enclosure format for a more streamlined build. The bypass switch PCB is integrated.


In stock

Project overview

A classic 80’s distortion pedal, this one needs no introduction. This version can be built with either 3 or 4 knobs (adding the well-known “Sweep” mod), with the Filter knob having two possible orientations to keep things symmetrical.

It also incorporates a switch for the clipping diodes. One side is stock while the other side allows a number of possible modifications, including a “softness” trimmer (clipping threshold control) and plenty of room to stack diodes or use LEDs.