With original late-70s Op-Amp Big Muffs selling for exorbitant prices, Mike Matthews decided to take the power to the people and reissue the classic pedal at a price that players could afford! The circuitry of the new EHX Op-Amp Big Muff Pi —sometimes also referred to as the IC or V4 Big Muff— has been faithfully re-created while several practical enhancements have been added including a compact, die-cast chassis and true bypass switching.