Electro Harmonix Nano Op Amp Big Muff

An Op-Amp Big Muff: The "V4 / IC" Era Revamped

When the original Op-Amp Big Muffs (late '70s) started becoming hard to find and overpriced, Electro-Harmonix decided to put this iconic version back into the hands of musicians. This Op-Amp Big Muff Pi captures the spirit of the "IC / V4" circuit, known for its sharper character and crunchier grain compared to other Big Muff variants. The reissue preserves the sonic DNA of the era while adding genuinely useful daily improvements: compact enclosure, modern construction, and True Bypass switching.

Who Is It For, Which Styles, and In What Contexts?

This pedal is aimed at all guitarists seeking a thick fuzz, expressive and immediately inspiring, from beginner level (simple controls) to advanced (stacking, chain placement, use of the Tone switch). It excels in alternative rock, grunge, indie, stoner, doom, shoegaze, yet remains just as formidable for lead playing in a blues-rock context when dialing in the Sustain and playing with the guitar's volume.
In the studio, it adds a dense saturation layer, ideal for doubling rhythm guitars and creating a "wall of sound." Live, its compact size and True Bypass make it a reliable pedalboard fuzz, with the Tone Bypass switch perfect for cutting through a mix or triggering a more aggressive passage without changing all the settings.

Settings, Controls, and Design: Simple, Effective, Stage-Ready

The Op-Amp Big Muff Pi goes straight to the point: three potentiometers and one switch cover a wide palette. The Volume controls output level, the Sustain manages gain and note length (from smooth saturation to fuzz that sustains "infinitely"), and the Tone sculpts the bass/treble balance to shift from a dark, massive sound to a more incisive fuzz.
The Tone Bypass switch removes the tone section from the circuit for a more direct, rawer sound with an immediate impact feel. Practical note: on this reissue, the switch behavior is designed to remain usable in real conditions, avoiding level surprises when switching modes. Add to that a footswitch with status LED and True Bypass switching: you get a pedal that's simple to dial in, easy to use, and particularly effective on stage.

The Sound

Expect a dense, snappy, and ultra-sustained fuzz, with a clear attack and a grain that can become a true "wall of guitars" when pushing the Sustain. Where some fuzzes get muddy in the lows, this op-amp version willingly retains a sense of crunch and presence, making it very convincing for heavy riffs, space-filling power chords, and thick, singing leads.
It responds very well to playing dynamics: hitting harder thickens the saturation, and lowering the guitar volume brings back a tamer drive (without losing the Big Muff identity). In terms of inspirations, this version is especially sought after by fans of textures like Billy Corgan (The Smashing Pumpkins) and guitarists wanting a fuzz capable of switching from a sculpted tone (Tone active) to a rawer flood (Tone Bypass) in one gesture.

Technical specifications

Effects	Compressor / Sustainer, Fuzz, Distortion	Type	sector
Format	Pedal	Use	electric guitar
EQ	Tone	Color	Orange

Effect pedal	fuzz / distortion / sustainer	Input impedance	55 kOhm
Potentiometers	Volume, Tone, Sustain	Power supply	9V DC (center negative)
Switch	Tone Bypass (activate/remove Tone section)	Required power supply	9V DC (center negative)
Footswitch	effect on/off	Consumption	5 mA
Input	6.35mm Jack (instrument)	Recommended adapter	capable of supplying at least 25 mA
Output	6.35mm Jack (to amp)