Big Muff Pi

The Big Muff Pi, in its different incarnations, is probably Electro-Harmonix's most popular product. This four-transistor fuzzbox is one of the first high-gain distortion units on the market. Its characteristic dirty, harmonically rich distortion tone, combined with its reliability and accessible price have made it greatly popular. It is also the origin of the Big Muff tone control.

Versions (USA)

Triangle PNP

So called for the layout of the controls, this is the original Big Muff. It's the most difficult to find and typically the most expensive to purchase. The Triangle Muff has a slider switch to turn it on or off in addition to the bypass stompswitch, and doesn't feature a LED indicator or a DC connector. Uses PNP transistors - positive ground.

Model Number: EH-3003
Release Year: Early-Mid 70's
Original Retail Price: $39.95US

• Schematic at GEOFEX
• Aron's Site Dragonfly's layout and parts list
• Uzzfay Utsgay Original PC board artwork, layout, and gut shots.

Triangle NPN

Another incarnation, uses NPN transistors, and a little less gain.

Ram's Head

Total change of look, now it's housed in a bigger box, pots are now in a row, and letters are red. Uses PNP transistors. A little less gain than the first Triangle. The tone circuit gives it a pronounced mids scoop, making it tricky to use in a band context.

Third edition

With the graphics currently associated with the american Big Muff. NPN transistors. Wilder and more "out of control".

Third edition with tone bypass

Same circuit except some minor changes (3 capacitors change from 1uF to 0.1) and a switch to bypass tone control, which brings more mids to the sound.

Opamp

Hated by some, loved by others, changed from transistors to op-amps. OpAmp Big Muff

Further reading

• Versions
• RonSound's article on Muff family history
• Big Muff and Guitar Effects Museum Lot's of BMP photos.