Electro-Harmonix OP Amp Big Muff

Sometimes also referred to as the IC or V4 Big Muff, the original circuitry has been faithfully re-created for the reissue, while several practical enhancements have been added including a compact, die-cast chassis and true bypass switching.  

The pedal relies on op-amps rather than transistors and three gain stages rather than four, to create its sound. It features standard controls—Sustain, Tone and Volume—plus a Tone toggle switch for bypassing the tone circuit. It comes equipped with a 9V battery or can be powered by an optional 9-volt AC adapter.