RCO Pedals Rupture Fuzz (modded Fuzzly Bear/BossTone build) 2026 - Raw aluminum with caution orange knobs

The Rupture Fuzz is a trace by PedalPCB of the KMA Machines Fuzzly Bear, itself a tweaked Jordan BossTone circuit. This build in particular is tweaked/modded even further to add a three-way toggle switch to select the clipping diodes used in the circuit as well as a two-way toggle to change the voicing, sort of a fat switch to bring out the low end frequencies useful for bass, down tuned guitars and even single coils.

On its own, this fuzz sounds darn good. Put it in front of a driven amp and it sounds incredible. Use the Clipping toggle to select between the stock four silicon diodes, a diode lift and two yellow LED’s for a wider range of fuzz/dirt and the Voice toggle to add some oomph. Sag biases the voltage to the second transistor and works in tandem with the Gain knob.

Between the Fuzz, Sag and Clipping controls, the Rupture Fuzz can go from a gritty overdrive, to fully saturated fuzz and all the way to doom territory in an amp on the edge of breakup and the Voice toggle in the up position.

Controls are Level, Gain and Sag (bias control). Three-way toggle on left is Clipping settings are stock silicon diodes (down), diode lift (middle) and yellow LED’s (up). The two-way toggle is Voice and settings are stock (down position) and fat (up position).