Electro-Harmonix Op-Amp Big Muff Pi

THE ULTIMATE FAITHFUL REPRODUCTION OF THE LATE-1970S OP-AMP CIRCUIT THAT DEFINED THE CRUNCHY, MID-FORWARD SMASHING PUMPKINS TONE.

Original owner. Non-Smoking studio.

Pedal used for only a few hours and never set on the ground.

This pedal is Electro-Harmonix's precise nano-sized recreation of the late-1970s IC (Op-Amp) Big Muff Pi, famous for its distinct aggressive crunch and mid-range cut. Unlike traditional transistor-based Big Muffs, it utilizes operational amplifiers and a reduced gain stage count to deliver a punchier, more wall-of-sound distortion character made legendary on alt-rock classics like Siamese Dream. Whether you need soaring lead sustain or massive, tight-tracking rhythm distortion that cuts cleanly through a dense mix, this analog circuit delivers iconic late-70s fuzz with modern pedalboard convenience.

Features

• Authentic Late-70s IC Circuitry: Meticulously engineered to replicate the exact op-amp gain architecture and aggressive frequency response of the rare 1978 original.
• Tone Bypass Switch: Dedicated switch completely removes the tone control circuit from the signal path for a massive, un-scooped, full-frequency raw volume boost.
• Punchy Mid-Forward Response: Provides sharper attack, increased mid-range presence, and tighter low-end focus compared to standard transistor Big Muffs.
• True Bypass Switching: Features high-quality mechanical true bypass routing to preserve complete signal integrity and original tone when disengaged.
• Pedalboard-Friendly Nano Enclosure: Housed in EHX's compact, die-cast chassis designed to maximize pedalboard space while providing maximum road durability.

*Power Supply NOT Included. Uses a standard center-negative 9 Volt DC power supply.