Erupter

The Erupter is a one-knob fuzz built around a classic low-parts-count fuzz topology. Volume and fuzz are fixed at their maximum, so the sound is controlled only by the Bias knob. At the centre detent the tone is big and round with a slight volume boost and long sustain. Turning the knob counterclockwise gives a more gated sound with lower output. Turning it clockwise gives a louder, cleaner and more refined fuzz.

A buffered front end and transformer-based pickup simulation let the pedal sit before or after other effects, including a wah, and respond well to the guitar's volume control for clean-up. The circuit uses carbon composition resistors, metallized polyester film capacitors, Sprague and BC electrolytic capacitors, and NOS hand-matched low-gain silicon transistors chosen for temperature stability.

The pedal uses true bypass with electronic relay-based switching, so no audio passes without power. It runs from a 9 V battery or a 9 V DC supply with a 2.1 mm negative-center barrel and draws 9 mA. Higher voltages must not be used. The maker lists the model as discontinued.