The ThorpyFX Muffroom Cloud is a fuzz pedal built around the classic Big Muff circuit, rebuilt from the ground up by UK builder Adrian Thorpe. What sets it apart from a stock Muff is its EQ: instead of a single tone control, it carries active Treble and Bass knobs, so the smooth, saturated fuzz can be reshaped far more aggressively than a vintage-style Muff allows12.
ThorpyFX announced the pedal on July 22, 2015 from Wiltshire, UK, as the company's second offering to market1. Guitar.com's reviewer Chris Vinnicombe described it as an analog fuzz pedal with active EQ, made in the UK2.
A Big Muff-style fuzz with active treble and bass
The Muffroom Cloud started from a question Thorpe set himself: can you build a Muff style fuzz that beats the 1971 Triangle Big Muff?1 The design takes the classic Big Muff circuit and rebuilds it from the ground up, and Gearnews found the result "keeps that classic singing sustain just with a far more powerful and controlled EQ section"3.
The controls are the familiar Muff layout plus the second EQ band:
| Control | What it does |
|---|---|
| Volume | Sets the pedal's output level1 |
| Sustain | Sets the amount of fuzz and sustain1 |
| Treble | Active treble EQ, cuts or boosts the top end1 |
| Bass | Active bass EQ, cuts or boosts the low end1 |
The launch release describes the result as "smooth and saturated fuzz that can be dramatically altered by adjusting the powerful active" Treble and Bass EQ1. For a player used to a passive Muff tone knob, the active bands mean real cut as well as boost, which is useful for taming a bright amp or fattening a thin one.
The build is aimed at pedalboard use and rough handling: recessed knobs, a sloped front and top mounted jacks1. Inside, Guitar.com found "a thick, gold-plated PCB housing metal film resistors with a one per cent tolerance and WIMA and Panasonic capacitors"2. The enclosure is laser cut and laser etched stainless steel in a Vivid Orange powder coat1, with a laser-etched graphic depicting a stylised hydrogen bomb schematic2.
Power and connections
The pedal runs on 9-volt operation with a standard DC input1, and the original version also takes a 9V battery2. Input and output are top-mounted Neutrik jack sockets, with the nine-volt PSU connector also on top2. Switching is true bypass12.
ThorpyFX has since dropped batteries from its pedals. Asked in a 2020 interview whether the company still fits battery compartments, Adrian Thorpe said: "We used to. We don't any more. It's a waste."4 The battery option applies to the original Muffroom Cloud, not necessarily to later ThorpyFX stock.
History: ThorpyFX's second pedal
Adrian Thorpe launched his first pedal in 2015, and the Muffroom Cloud followed the same year as ThorpyFX's second offering15. The company went on to build a larger roster, and by 2026 MusicRadar counted four pedals in the line, with the Fallout Cloud taking a winning drive pedal award in its Gear Of The Year Awards5.
The tone stack was a collaboration. Thorpe told Guitar.com:
"A friend of mine, Dan Coggins, who was the designer of Lovetone pedals and now Dinosaural, collaborated with me on it"2
Coggins's background with Lovetone, the revered 1990s UK effects maker, gives the EQ design some pedigree for players who follow that history2.
Gearnews placed the Muffroom Cloud among its top five fuzz pedals of 2016, calling it "a versatile, Muff-style fuzz from UK builder Adrian Thorpe"3, and in a later news piece compared it to a vintage Big Muff, describing the regular TS808 and Big Muff as "the closest pedals to The Gunshot and The Muffroom Cloud" among vintage counterparts6. The pedal also appeared as demonstration gear on That Pedal Show's delay basics episode7.
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Questions
Does the ThorpyFX Muffroom Cloud take a battery?
Yes. The original Muffroom Cloud runs on a 9V battery or mains power through its nine-volt PSU connector. ThorpyFX has said its newer pedals no longer include battery compartments, so the battery option applies to the original version rather than later ThorpyFX stock generally214.
Is the Muffroom Cloud true bypass?
Yes. Both the launch press release and the Guitar.com review list a true bypass on/off footswitch, so the pedal is out of the signal path entirely when switched off12.
How much does the ThorpyFX Muffroom Cloud cost?
At launch on July 22, 2015 it was listed at $306 retail in the US. The Guitar.com review gave the UK price as £184.99. Pricing for remaining stock may differ today12.
Where is the Muffroom Cloud made?
In the UK. ThorpyFX is based in Wiltshire, and the Guitar.com review describes the pedal as an analog fuzz pedal with active EQ, made in the UK28.
Who designed the Muffroom Cloud tone stack?
Adrian Thorpe designed the pedal, with Dan Coggins collaborating on the tone stack. Coggins was the designer of Lovetone pedals and later Dinosaural2.
Sources (8)
- Thorpy FX Releases The Muffroom Cloud Fuzz, Premier Guitar, 2015-07-22
- ThorpyFX Muffroom Cloud fuzz pedal review, Guitar.com, 2015-08-27
- Top 5 Fuzz Pedals: The best dirt boxes of 2016, gearnews.com, 2016-05-18
- Thorpy FX, Stompbox Book (stompboxbook.com), 2020-04-12
- ThorpyFX Warthog review, MusicRadar, 2017-01-22
- The Warthog and The Peacekeeper: new boutique pedals from ThorpyFX for 2016, gearnews.com, 2015-12-29
- Delay Basics: Uses, Misuses & Why Quick Delay Times Are Awesome, That Pedal Show, 2015-11-13
- Manson Guitar Works Supermassive Black Fuzz review | Guitar World, Guitar World, 2026-01-27
