Electro-Harmonix BIG MUFF PI 2 Dual Op-Amp Fuzz PedalElectro Harmonix Founder and President, Mike Matthews and serial inventor Bob Myer go way back. Together, they designed the very first Big Muff and had a working relationship throughout EHXs storied history. Always innovating, Bob was known to present Mike with updated designs to keep up with available technology of the times. As the process goes, designs get selected and others get put aside and forgotten about. The Big Muff Pi 2 Dual Op Amp design