Muff Fuzz (Op Amp)

Very early EHX gain box that originally plugged straight into the guitar.

Different flavour to the original transistor based circuit, so worth checking them both out for vintage fluffy tones.

Note: this is NOT a Big Muff Pi. Different thing altogether.

Board-mounted pot for minimal wiring and easy enclosure mounting.

Full kits are available with optional standard sized 1590B enclosure with battery, or a mini 1590A (36 x 90mm) enclosure with DC power only, though be aware that you'll be wiring in a very confined space.

If you want the PCB without parts there's a link for that at the bottom of the page.

Partial kit: PCB, all board-mounted components, pots.

Full kit: As above, plus footswitch and appropriate daughterboard/components for your selected bypass type (see Downloads section for details of those), jack sockets, DC socket, battery snap, hook-up wire, LED.

Enclosure (pre-drilled) is available as an option with full kits, and can take a battery if desired with footswitch positioned 22mm higher, closer to the controls, in a 1590B. 1590A will not take a battery. Knobs are not included.

Builds are only available with full kits including enclosure. Please choose appropriate knobs.

Inspired by: Muff Fuzz

Difficulty: Easy

PCB size: 30 x 22mm

Knobs required: 1

Enclosure: 1590B, 1590A

Download the INSTRUCTION PDF

Product Code: FuzzyMuff

Brand: Pedal Parts

Weight: 130.0g

Product Condition: New

Kit type* Allow for battery?*

£20.40 inc. tax

£17.00 ex. tax

? Tax based on United Kingdom.

Customer Reviews

1 review(s) posted (write review)

Try out different diodes.
"Really easy pedal to assemble. The stock sound is pretty underwhelming: quiet, slightly overdriven, a little muddy. I took out the clipping diodes and tried it again, and that completely changed the pedal. Removing the diodes turned the pedal into a huge sounding fuzz-distortion with double the amount of volume. I tried out different diodes, but I settled on one of the Russian germanium diodes that came with the kit. One diode tamed the pedal some with only about a 10% drop in volume; two diodes puts it back into sad overdrive territory." awkbinoc - 16 November 2021

Reply From FuzzDog

Thanks for reviewing. The original is indeed a basic drive, so if it’s not what you’re after it should be avoided. Glad you found a setup that worked for you.