HeliosVintage Distortion

From the vendor

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.

The Helios Vintage Distortion is a recreation of the Pro Co RAT Distortion. First released in 1978, it went through several iterations over the next few decades and was released under other names like the RAT2 and Turbo RAT. The core circuit remained essentially the same throughout its lifespan.

The RAT can be considered an evolution of the MXR Distortion+. It has the same basic op-amp gain stage followed by diode-to-ground clipping. However, it also significantly alters the EQ in the op-amp stage as well as adding a tone control and output buffer.

The Helios adds two modifications: a clipping switch to select between three different sets of diodes, and a Sweep control that changes the EQ and gain structure.

Note: The PCB-only version of this project uses a type of capacitor that has been temporarily discontinued by WIMA. Please see our news article about the issue and the substitution spreadsheet for project-specific recommendations. We are stocking a limited supply in the mean time. The build document has not yet been updated to reflect this. It does not impact the kits.