PEDAL BENCH
by Stompbox Labs
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Fuzz1969· Electro-Harmonix (USA)Pro

Electro-Harmonix Big Muff Pi

Four-stage transistor fuzz with diode clipping in two stages — walls of sustain.

About

A four-stage circuit: input booster, two cascaded clipping stages (each with diodes across the feedback resistor), a scooped passive tone stack, and an output recovery amp. Produces enormous sustain and a deeply scooped midrange.

Signal chain preview

6 stages
Input
Q1: input common-emitter booster
Q2: 1st clipping stage with anti-parallel diodes in feedback
Output
Unlock full signal chain

Quick facts

  • The 'scooped' tone stack is what gives the Muff its signature 'recessed' midrange.
  • Cascading two soft-clipping stages produces extreme sustain without losing note pitch.
  • Variants are legion: Triangle (1969), Ram's Head ('73), Op-Amp (~'78), Russian Sovtek ('90s).
  • Used by David Gilmour, Billy Corgan, and Jack White, among many others.

Controls

  • Sustain (100k log)
  • Tone (100k linear)
  • Volume (100k log)

Mod recipes Pro

4 mods
Mids Switch
Civil War tone (Sovtek '91)
Clipping diode swap
Input cap upgrade
Unlock all 4 mods

References

Community-sourced (ElectroSmash, Kit Rae's Big Muff history). Targets the 1973 Ram's Head spec.