125B · 3 knobs
Operational Muff
Based on the Electro-Harmonix Op-Amp Big Muff Pi· 18 other boards clone it
- Category
- Fuzz· Muff type fuzz
- Difficulty
- Intermediate
- Price
- €9.90out of stock
Heads up Builders widely report inconsistent quality from PCB Guitar Mania boards, and whether a given board works is a gamble. Read recent forum reports before ordering.
From the vendor
Project Overview
With authentic late-70s Op-Amp Big Muffs selling for absurd prices on the vintage market, Mike Matthews decided to take the power to the people and reissue this classic pedal at a price that players could actually afford!
We wanted to go a step forward by allowing anyone to build their version of the Op-Amp Big Muffs.
Now you can get all the classic sounds that made this pedal so popular without having to break the bank.
Introduction
Ready to make your tone muffin-style? Inspired by Op-Amp Big Muff Pi, we made the Operation Muffin, a true bypass pedal that faithfully recreates the classic circuitry of the original while adding enhancements for a modern sound.
This is the sound of rock and roll. In 1993 the Op-Amp Big Muff was popularized by Billy Corgan on his masterpiece Smashing Pumpkins album Siamese Dream. Since then, it has become one, if not the most, iconic fuzz sound ever created!
This pedal leans on op-amps instead of the usual transistors and three gain stages rather than four to create its signature sound.
It has controls for Tone, Sustain, and Volume, plus a Tone Bypass switch and a true bypass switching for maximum signal integrity in bypass mode, all while fitting in a practical 125b enclosure.
I could write a lot o content describing the Op-Amp Big Muff Pi sounding, but it’s better to quote the historian Kit Rae, one of the biggest Muff collectors of all time:
“A huge, crushing Big Muff sound with more crunch…
great for grungy,
wall-of-sound distortion,
heavy rhythm playing,
and heavy leads.”
Controls
Potentiometers
• Sustain
• Tone
• Volume
Switches
• Tone Bypass
For any technical questions regarding this build don’t forget to check out our Facebook Group and our forum at Free Stomp Boxes.
Operational Muff – Building Docs
Operational Muff – Drilling template
Schematic
The schematic is in the vendor's build document, page 5. Open the build document. No KiCad fragment has been drawn for this circuit yet.
Parts list 46 rows
Report a wrong parseGot parts in a drawer? See what you can build with them.
| Ref | Value | Normalized | Type | Notes |
|---|---|---|---|---|
| Resistors 20 | ||||
| R1 | 56K | 56k | ||
| R2 | 330K | 330k | ||
| R3 | 220K | 220k | ||
| R4 | 220K | 220k | ||
| R5 | 10K | 10k | ||
| R6 | 47K | 47k | ||
| R7 | 47R | 47 | ||
| R8 | 8K2 | 8.2k | ||
| R9 | 470K | 470k | ||
| R10 | 820K | 820k | ||
| R11 | 560K | 560k | ||
| R12 | 62K | 62k | ||
| R13 | 1M | 1M | ||
| R14 | 47K | 47k | ||
| R15 | 47K | 47k | ||
| R16 | 5K6 | 5.6k | ||
| R17 | 1K2 | 1.2k | ||
| R18 | 100K | 100k | ||
| R19 | 47R | 47 | ||
| R20 | 1m | 1M | ||
| Capacitors 13 | ||||
| C3 | 10n | 10n | ||
| C4 | 4n7 | 4.7n | ||
| C7 | 150p | 150p | ||
| C8 | 220n | 220n | ||
| C9 | 150n | 150n | ||
| C10 | 100n | 100n | ||
| C12 | 120n | 120n | ||
| C2 | 1u | 1u | ||
| C5 | 10u | 10u | ||
| C6 | 4u7 | 4.7u | ||
| C11 | 1u | 1u | ||
| C13 | 220u | 220u | ||
| C1 | 150n | 150n | ||
| Diodes 8 | ||||
| D1 | 3mm | 3MM | ||
| D2 | 1N4148 | 1N4148 | ||
| D3 | 1N4148 | 1N4148 | ||
| D4 | 1N4148 | 1N4148 | ||
| D5 | 1N4148 | 1N4148 | ||
| D6 | 1N4148 | 1N4148 | ||
| D7 | 1N4148 | 1N4148 | ||
| D8 | 1N5817 | 1N5817 | ||
| ICs 2 | ||||
| IC1 | UA741CP | UA741CP | ||
| IC2 | JRC4558 | JRC4558 | ||
| Potentiometers 3 | ||||
| SUSTAIN | B10K | B10k | Potentiometer | |
| TONE | B10K | B10k | Potentiometer | |
| VOLUME | B100K | B100k | Potentiometer | |
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