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Graviton Metal Distortion

Based On
Effect Type
Metal Distortion
Build Difficulty
Project Summary
A unique distortion effect favored by extreme metal guitarists for its characteristic “buzzsaw” sound. It also works very well as a versatile high-gain effect in other styles of music.

Complete Kit

What's included?
PCB, finished enclosure, hardware,
and all electronic components.


In stock

Graviton Metal Distortion printed circuit board

PCB Only

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


In stock

Project overview

The Graviton Metal Distortion is a clone of the BOSS® HM-2 Heavy Metal, first released in 1983 and discontinued in 1991. The HM-2 was largely overlooked while it was in production, but in the mid-1990s it got the attention of a few bands in the Swedish death metal scene who developed something of a signature guitar tone by turning all the knobs to 10, often running it into a cheap solid state amp. Here is the video that first exposed this technique:

Despite the reputation it enjoys in the extreme metal community, it is far from a one-trick pony. It’s a very flexible pedal with a balanced high-gain distortion tone that works well in many styles of music.

This circuit also made an appearance as the DOD FX-56 American Metal, released in 1984. While the pedals don’t really sound the same, the American Metal has almost the exact same circuit layout, just with different parts values and with the two tone knobs combined into one. You can build the American Metal with the Graviton PCB.

Demo Video

Check out RJ Ronquillo’s demo video of the Graviton Metal Distortion.
Watch on YouTube →