Pedal Profile: The EHX Op-Amp Big Muff — Fuzz With Bite
If you're into heavy fuzz that cuts through the mix without turning into a mess of low-end mud, the Electro-Harmonix Op-Amp Big Muff should be on your radar. Made famous by Billy Corgan of The Smashing Pumpkins during the Siamese Dream era, this version of the iconic Big Muff circuit trades the usual transistor-based gain stages for op-amps — and the result is sharp, punchy, and undeniably aggressive.
🧪 What Makes It Different?
Unlike the standard triangle, Rams Head, or NYC Big Muffs that use discrete transistors for gain, the Op-Amp Big Muff uses operational amplifiers (TL072s, specifically) to drive its clipping stages. This results in:
Tighter low end
Slightly more compression
Faster attack and more mids (especially when the tone switch is engaged)
It’s not “transparent” by any means — it’s a wall of fuzz — but it retains clarity in a mix better than many traditional fuzz pedals.
🎸 How It Sounds
Expect:
A thick, saturated fuzz with a harmonic-rich character
Enough sustain for days
Less flubby bass than transistor Muffs
A pronounced midrange when the Tone Bypass switch is engaged (which can also boost volume)
🎧 Hear it in action — We demo the EHX Op-Amp Big Muff through the Wretched Beast amp on our YouTube channel.
👉 Watch the full demo to hear how it punches through a high-gain tube circuit.
⚙️ Simple Controls, Big Payoff
Volume – loud enough to slam the front of your amp
Tone – classic Muff-style EQ sweep
Sustain – from gritty drive to full-on fuzz wash
Tone Bypass Switch – jumps straight past the tone stack for a louder, less-scooped sound
🧠 Who It’s For
Players who want fuzz with more punch and less scoop
Fans of '90s alt tones (Smashing Pumpkins, Silversun Pickups)
Pedal nerds curious about Muff variants
Anyone who tried a standard Big Muff and felt it was too wooly
🧰 Final Thoughts
The EHX Op-Amp Big Muff isn’t subtle — and that’s the point. If you want a fuzz that hits hard without washing out, this one's a beast in a surprisingly affordable box. It stacks well, it records well, and it doesn’t disappear live. Not bad for a design that started as a weird sidestep in the Big Muff family tree.
Want a fuzz pedal that sounds huge but still feels tight? Give the Op-Amp Big Muff a spin — or check out our own tre_audio Fuzz if you want something even nastier. 👀
There’s never enough fuzz, that’s why we at tre_audio built the tre_audio FUZZ Pedal. FUZZ is based on the classic fuzz pedals that you know and love. It is a transistor-based fuzz pedal that will give your instrument the harmonic, saturated sustain that you want and expect from a fuzz pedal. As with most of our gear, we’ve pushed this circuit to its limits with higher clipping circuit amplification and less attenuation. This gives the pedal a ton of fuzz.