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SUSTAINTONEVOLUME

125B · 3 knobs

PCB Guitar Mania

Operational Muff

Based on the Op-Amp Big Muff Pi· 1 other board clones it

Category
Fuzz· Muff type fuzz
Controls
Sustain · Tone · Volume
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

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Resistors 20
R156K56k
R2330K330k
R3220K220k
R4220K220k
R510K10k
R647K47k
R747R47
R88K28.2k
R9470K470k
R10820K820k
R11560K560k
R1262K62k
R131M1M
R1447K47k
R1547K47k
R165K65.6k
R171K21.2k
R18100K100k
R1947R47
R201m1M
Capacitors 13
C310n10n
C44n74.7n
C7150p150p
C8220n220n
C9150n150n
C10100n100n
C12120n120n
C21u1u
C510u10u
C64u74.7u
C111u1u
C13220u220u
C1150n150n
Diodes 8
D13mm3MM
D21N41481N4148
D31N41481N4148
D41N41481N4148
D51N41481N4148
D61N41481N4148
D71N41481N4148
D81N58171N5817
ICs 2
IC1UA741CPUA741CP
IC2JRC4558JRC4558
Potentiometers 3
SUSTAINB10KB10kPotentiometer
TONEB10KB10kPotentiometer
VOLUMEB100KB100kPotentiometer

Other boards based on the Op-Amp Big Muff Pi