The ThorpyFX Warthog is an analog distortion pedal made in the UK by ThorpyFX, the company founded by British Army Major Adrian Thorpe1. ThorpyFX describes it as "our American flavour distortion" and sums up its circuit as "Think a little RAT-like but so much more"2. The RAT comparison comes from the core distortion circuit, but the Warthog adds a second gain stage, a preamp at the start of the circuit, controlled by its Caliber knob3.
The range is wide. ThorpyFX says the pedal was "designed to be the distortion to beat all others; however it ended up being so much more", spanning crystal clean boost through to full distortion, and with the Caliber and Gain controls cranked, "a crushing distortion with fuzzy overtones at the very extremes of travel"24. Gearnews reported at launch that ThorpyFX claimed a range from clean boost all the way through to an American-style distortion5.
A RAT-like distortion with a second gain stage
The Warthog's circuit lineage places it among RAT-style distortions. Guitar Pedal X included it in a 2024 roundup of favorite compact RAT-style distortion pedals, alongside pedals like the Foxpedal Wrath V2, which Delicious Audio described as a "RAT inspired distortion"910. What separates the Warthog from a straight RAT clone is the preamp stage at the front of the circuit. MusicRadar's reviewer, Trevor Curwen, explained that the Caliber control "controls a second gain stage - a preamp at the start of the circuit"3.
That preamp is what lets the pedal cover clean boost as well as distortion. RockBoard's PedalPedia entry for the MKI lists it as a "DISTORTION BOOSTER" with an analog circuit, and notes the maker's claim that it delivers the biggest range of tones of any overdrive/distortion pedal on the market, from crystal clean boost through to distortion6.
The controls: Volume, Tone, Gain and Caliber
Four knobs set the sound. Guitar Pedal X lists them as Volume, Tone, Gain and Caliber, describing Caliber as a Character/Girth control8.
| Control | What it does |
|---|---|
| Volume | Sets the output level |
| Tone | Rolls off high end as you turn it up1 |
| Gain | Sets the amount of distortion; cranked with Caliber it gives crushing distortion with fuzzy overtones at the extremes of travel2 |
| Caliber | Controls a second gain stage, a preamp at the start of the circuit3 |
The Caliber knob is where most of the pedal's character lives. Guitar Pedal X's reviewer wrote that "the magic is mostly in the 'Calibre' control - which at times adds more distortion, or tightens things up further or just imparts more texture and flavour"8. Guitar.com's review put it another way, saying "the calibre brings a 'secret sauce' of saturation, grit and heat to the table"1.
Build and power
The current MKIIB uses what ThorpyFX calls "a beautiful laser engraved anodised aluminium centre console wrapped in a tough powder coated baseplate", with recessed knobs and top mounted jacks2. At launch, the original version was housed in a custom laser etched stainless steel case with recessed controls5. Power comes from a 9V DC center-negative supply drawing 25mA26, and the original version could also run on a battery1.
Versions: MKI and MKIIB
The Warthog has gone through more than one enclosure. The original MKI was the stainless steel cased pedal launched in February 20165. ThorpyFX's current product page presents "The all new look WARTHOG (MKIIB)"2. In between, a smaller version circulated: on That Pedal Show in November 2018, Mick said "the other thing I've got here is a new smaller warthog thought we was kind enough to send me one"11.
If you are buying used, check which version you are getting. The MKI came in a larger stainless steel case, while later versions are smaller, and the current MKIIB uses an anodised aluminum and powder coated enclosure.
Where it came from
What reviewers said
"This really could be the only dirt pedal you'll need."
MusicRadar review3
Guitar Pedal X kept it in its 2024 RAT-style roundup, singling out the Caliber control as the heart of the pedal8.
On That Pedal Show, Mick demonstrated the smaller Warthog alongside other ThorpyFX pedals, noting that ThorpyFX had sent him the new compact version11.
Videos
ProGuitarShopDemos
ProGuitarShopDemos
ThorpyFx
Questions
What does the Calibre knob do on the Warthog?
Calibre controls a second gain stage, a preamp at the start of the circuit, ahead of the main RAT-like distortion stage. Guitar Pedal X's reviewer found it sometimes adds more distortion, sometimes tightens the sound, and sometimes just adds texture and flavor. Cranked together with Gain, it produces crushing distortion with fuzzy overtones at the extremes of travel.
Is the ThorpyFX Warthog true bypass?
Yes. Guitar.com's review describes it as a true-bypass overdrive/distortion pedal, so with the pedal off the signal passes through without buffering.
How much current does the Warthog draw?
The maker lists a current draw of 25mA, which RockBoard's PedalPedia entry for the MKI confirms. It runs on a 9V DC center-negative supply, and the original version could also run on a battery.
Who designed the ThorpyFX Warthog?
The Warthog was designed by Adrian Thorpe, a British Army Major who founded ThorpyFX. The pedal is made in the UK, and Thorpe has since co-designed pedals for other brands, including Victory's V1 range and Redbeard Effects' Red Mist MKIV.
Sources (11)
- ThorpyFX Warthog review, Guitar.com, 2016-05-11
- WARTHOG | Distortion, ThorpyFX
- ThorpyFX Warthog review, MusicRadar, 2017-01-22
- JUDGE DEATH DEATHBRINGER, ThorpyFX
- The Warthog and The Peacekeeper: new boutique pedals from ThorpyFX for 2016, gearnews.com, 2015-12-29
- Warthog MKI by ThorpyFX, RockBoard PedalPedia, 2026
- NAMM 2016: ThorpyFX releases two new pedals the Peacekeeper & Warthog, Guitar.com, 2016-01-22
- Guitar Pedal X, Guitar Pedal X, 2024-08-30
- Veteran V2 Si by ThorpyFX, RockBoard PedalPedia, 2026
- Foxpedal Unveils Three Updated V2 Pedals: Magnifica, Refinery And Wrath, Delicious Audio, 2017-03-22
- Mick's Vlog: New Pedalboard Q&A Plus Maxon OD9 & Tru-Fi Colordriver Additions, That Pedal Show (YouTube), 2018-11-06
