EHX Big Muff Pi vs ProCo RAT
The Big Muff wins for massive scooped sustain — Gilmour-style lead tones and shoegaze walls of sound. The RAT wins for tighter, more midrange-present distortion that cuts through a band mix with more note definition.
EHX Big Muff Pi
The definitive sustain fuzz — four-stage cascaded transistor clipping producing massive, compressed sustain with the characteristic mid-scooped EQ. Used by David Gilmour, Kurt Cobain, Billy Corgan, and J Mascis to define grunge, shoegaze and classic rock fuzz.
Grunge, doom, shoegaze, and psychedelic players who want compressed, wall-of-sound fuzz — not for players who need touch-sensitive dynamic response
ProCo RAT
Harder-clipping distortion with a unique Filter control that runs backwards (clockwise = darker). Warmer and more compressed than the DS-1, with more amp-like harmonic content across a wider gain range.
Blues rock, alternative, post-punk, hard rock — harmonically rich distortion with more low-gain versatility
Tone Character
EHX Big Muff Pi
- ✓ Massive, compressed sustain
- ✓ Iconic mid-scooped fuzz character
- ✓ Original design still in production
- ✓ Multiple versions (Ram's Head, Tone Wicker, etc.) available
- ✗ Mid scoop can disappear in a full band mix
- ✗ Does not clean up with guitar volume like Fuzz Face
- ✗ Relatively large enclosure
ProCo RAT
- ✓ Versatile Filter control
- ✓ Warmer character than DS-1
- ✓ Works as overdrive at low gain
- ✓ Classic studio pedal on thousands of records
- ✗ Filter control is counter-intuitive (inverted)
- ✗ Doesn't clean up with guitar volume
- ✗ Noisy at maximum gain
When To Choose Each
Lead players who want huge sustaining fuzz — David Gilmour, Jack White, Billy Corgan and shoegaze players.
Alt-rock and blues-rock players who want aggressive distortion with better band-mix presence than fuzz.
Final Verdict — EHX Big Muff Pi vs ProCo RAT
Best for beginners
ProCo RAT
ProCo RAT scores higher on versatility (62/100) and lower on gain (68/100) — a more forgiving starting point than EHX Big Muff Pi.
Best for metal tones
EHX Big Muff Pi
EHX Big Muff Pi leads on gain (80/100) and bass response (40/100) — the two tonal pillars of metal playing.
Best value
EHX Big Muff Pi
At £79 vs £79, EHX Big Muff Pi delivers 0% cost savings. The tonal trade-off is meaningful.
Specification Summary
| EHX Big Muff Pi | ProCo RAT | |
|---|---|---|
| Price | £79 | £79 |
| Category | Fuzz | Distortion |
| Gain | 80/100 | 68/100 |
| Warmth | 45/100 | 55/100 |
| Treble | 50/100 | 52/100 |
| Bass | 40/100 | 45/100 |
| Versatility | 45/100 | 62/100 |
| Best for | Grunge, doom, shoegaze, and psychedelic players who want compressed, wall-of-sound fuzz | Blues rock, alternative, post-punk, hard rock |
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Frequently Asked Questions
Big Muff is a fuzz — huge, scooped, sustained. RAT is a distortion — tighter, more aggressive, with more midrange.
Big Muff for Gilmour-style sustain; RAT for more cut and note definition in a band mix.
RAT handles humbuckers well; Big Muff with humbuckers can get muddy — scoop the bass.
Big Muff: David Gilmour, Jack White, Billy Corgan. RAT: Kurt Cobain, Jeff Beck, Dave Grohl.