The ProTone Body Rot II is a distortion pedal built around the LM386 chip, a circuit that Guitar FX Layouts describes as "a slightly modded Krank Distortus Maximus"1. It grew out of ProTone's earlier Body Rot pedal: the Body Rot II "started off with the heart of the original Body Rot distortion pedal with some added tone shaping EQ"1. The pedal it draws on, the Krank Distortus Maximus, is a high-gain distortion that GuitarPCB's build document says delivers the aggressive tone characteristic of Krank's Revolution and Krankenstein amplifiers2, and which RockBoard's PedalPedia lists as distortion and equalizer3.
Controls and suggested pot values
The layout's control arrangement, as one builder wired it, runs "volume, treble, mids and bass, and the leftmost is gain"1. That gives the pedal a full EQ section on top of its gain stage, which is the added tone shaping that separates it from the original Body Rot.
| Control | Suggested pot |
|---|---|
| Gain | Leftmost position1 |
| Treble (highs) | 20K linear1 |
| Mids | 1 |
| Bass | 50K log, confirmed as a better sweep by a builder1 |
| Volume | 1 |
One quirk worth knowing before you build or modify one: the distortion control's lug 1 goes to ground, "so at zero all the signal is being dumped to the ground, hence the sound" cuts out entirely1.
A builder on the layout page found that swapping the LM386N-3 for a 386N-4 "fixes all the funny noises that 386 based distortion produces"1. Any LM386 will work for the chip, but the N-4 version is the one commenters settled on.
What players and builders made of it
The layout is "definitely verified", confirmed working by multiple builders on the Guitar FX Layouts page1. One builder reported the sound as "really focused and mean. Easily as good as the AMT S-1 Preamp", adding that it was not too noisy for the immense gain on tap and had very good EQ1.
The pedal's parent circuit has a strong reputation of its own. Guitar World's 2007 review of the Distortus Maximus concluded that it "delivers raw and raunchy high-gain distortion tones that sound exceptionally similar to those of K"4, and one builder on the Body Rot II page said the layout changed his mind about building the Distortus Maximus itself1.
Availability
The Body Rot II is hard to find. A 2024 comment on the layout page reported that a quick search turned up none for sale, "or much info outside of the video demo"1. The published stripboard layout is the practical way for most players to get one.
ProTone also made the Skumstortion, another distortion in the company's range.
Videos
JetCityMusic
The Fifth Fret
The Fifth Fret
Questions
What chip does the ProTone Body Rot II use?
The circuit is built around the LM386 chip. On the Guitar FX Layouts page where the stripboard layout was published, a builder noted that any LM386 will work for the chip, and another commenter found that swapping the LM386N-3 for a 386N-4 fixes what they called the funny noises that 386-based distortion produces.
Is the ProTone Body Rot II based on the Krank Distortus Maximus?
Yes. Guitar FX Layouts describes the Body Rot II as a slightly modded Krank Distortus Maximus, the high-gain distortion pedal that GuitarPCB's build document says delivers the aggressive tone characteristic of Krank's Revolution and Krankenstein amplifiers. The Body Rot II itself started with the heart of the original Body Rot pedal plus added tone-shaping EQ.
Where can you buy a ProTone Body Rot II?
It appears to be difficult to buy. A commenter on the Guitar FX Layouts page in 2024 said a quick search turned up none for sale and little information beyond the video demo. The layout itself is published there, so the practical route for most players is to build one from that verified stripboard layout.
What pot values are suggested for the highs and bass controls?
For the highs control, a 20K linear pot is suggested. For the bass control, a builder asked whether a 50K log pot could be tried for a better sweep, and that change was confirmed as working better.
Sources (4)
- Guitar FX Layouts: ProTone Body Rot II, Guitar FX Layouts (tagboardeffects.blogspot.com), 2025-05-14
- Krank-Distortus-Maximus-Build-Document.pdf, GuitarPCB, 2025-10
- Distortus Maximus by Krank, RockBoard PedalPedia, 2026
- Krank Distortus Maximus Distortion Pedal, Guitar World, 2007-03-28
