For 50 years, a forgotten schematic sat buried in dust and time – a concept waiting to be born. Now, its moment has come. The EHX Dual Op-Amp Big Muff 2 is here, delivering a completely new Big Muff voice unlike anything you’ve heard before.

THE PAST & PRESENT

In 2021, while on a research trip that led to the creation of the book Made On Earth For Rising Stars: The Electro-Harmonix Story, we had the privilege of digging through decades of materials, memorabilia, devices, and prototypes in the workshop of Bob Myer, the inventor of the EHX Big Muff. It was there we discovered it: a loose sheet of paper with a hand-drawn schematic labeled “BIG MUFF USING (2 DUAL OP AMPS)”.

This wasn’t just another circuit. It was Bob Myer’s own attempt to reimagine the original transistorized Big Muff circuit using the new cutting-edge Op-Amp technology that had emerged later in the 1970s.

For nearly 50 years, this “Lost Big Muff” design sat forgotten in his notebooks — until now. We found it. We built it. And have brought it to life.

WHAT MAKES THE BIG MUFF 2 DIFFERENT?

Once discovered, we breadboarded the circuit exactly as Bob drew it, and immediately knew we had something worth making. We found that Bob’s design is unique when compared to the now famous late 70s Op-Amp Big Muff designed by Michael Abrams. Different clipping arrangement, an extra gain stage and various other elements that made this lost version extremely special.

Where the original Big Muff delivers that iconic "sweet violin-like sustain," Bob's two dual Op-Amp approach pushes into more aggressive, cutting territory. It's the Big Muff DNA with a sharper edge, more volume, and the most pronounced low-end and midrange of any EHX Big Muff ever. It expresses Bob's vision of aggressive sustain and cutting presence, with the familiar Big Muff control layout you know and love. It’s the sound of what almost was.

Mike Matthews himself, after hearing our prototype, admitted it had "something special" even though it strayed from the traditional Big Muff voicing he typically preferred. Sometimes the best creations are the ones that don't follow the rules.

Controls:

• VOLUME - Controls the output volume. Left is less, right is more.
• SUSTAIN - Controls the amount of fuzz, which increases the sustain when turned up. Left is less, right is more.
• TONE - Controls the overall tone. Left is darker, right is brighter.
• POWER - 9VDC center negative, 18mA

Product specs