The JAM Pedals "Achenbach" Red Muck is a fuzz/distortion pedal in the Greek maker's Red Muck mk.2 line, a circuit JAM describes as inspired by the '71 Triangle and later Red Army/Civil War Big Muff designs. The maker positions it as covering singing sustain, dense saturation and large stoner-fuzz walls of sound, with a smoother, more authoritative voice than the circuits it draws on1. Like other Red Muck artwork versions, it is a limited, one-of-a-kind hand-painted pedal: the artwork on the pedal you receive will differ in detail from the product photos1.
The "Achenbach" is one of several artwork variants of the same mk.2 circuit, alongside the Relic, Feline, White Mountaintops, Lunar Muck and Noufaro versions. JAM Pedals states these share the same sound and differ only in the paint job1. There is also a separate Red Muck Bass built for bass players.
A Big Muff-style fuzz with a boost section
The Red Muck mk.2 circuit combines early Triangle and later Red Army/Civil War Muff influences. In JAM Pedals' words, it spans "lyrical sustain, varied compression and huge stoner-fuzz walls" with a smoother, more authoritative voice1. Delicious Audio, covering the mk.2, describes it simply as a Muff-style fuzz2.
What sets the mk.2 apart from a straight Muff clone is its boost section. The left footswitch engages a separately tuned section before the fuzz: JAM says it hits the front of the fuzz for thicker saturation, or works as a second high-gain stage when the main Gain control is set lower. An internal trimmer sets the boost's level1. That gives the pedal two footswitchable gain stages from one knob setup, a layout JAM also uses on its updated Rattler 2 and TubeDreamer MK2 designs.
A toggle adds a second voicing option: symmetrical clipping, which matches the Red Muck mk.1, or asymmetrical clipping for what the maker calls a different response and harmonic texture1.
The controls and footswitches
The control set is the classic three-knob Muff layout, plus two footswitches and a clipping toggle1.
| Control | What it does |
|---|---|
| Level | Sets output volume1 |
| Tone | Shapes the frequency balance1 |
| Gain | Controls saturation1 |
| Right footswitch | Engages the main fuzz effect1 |
| Left footswitch | Engages the boost section before the fuzz1 |
| Toggle | Selects symmetrical (mk.1-matching) or asymmetrical clipping1 |
An internal trimmer sets the boost level, so the boost's strength is set once with a screwdriver rather than from the top of the pedal1.
Artwork versions and the bass model
JAM Pedals sells the Red Muck mk.2 circuit in several custom artwork versions. The maker's own pages for each variant list the same family: Achenbach, Feline, Lunar Muck, Noufaro, Relic and White Mountaintops, all with the same sound and different artwork13456. Every limited artwork pedal is a one-of-a-kind hand-painted piece, and the pedal received will differ in detail from the photos shown1.
The Red Muck Bass is a separate product, not just an artwork variant. JAM describes it as "a full-bodied fuzz-distortion that brings Triangle and Red Army/Civil War Muff-inspired weight to bass without sacrificing definition"7. Its circuit draws on the same '71 Triangle and later Red Army/Civil War designs, with what the maker calls a smoother response, stronger mids and fat low end7.
| Achenbach Red Muck | Red Muck Bass | |
|---|---|---|
| Type | Fuzz/distortion1 | Bass fuzz/distortion7 |
| Controls | Level, Tone, Gain1 | Level, Tone, Gain7 |
| Left footswitch | Boost section before the fuzz, level set by internal trimmer1 | HIGH GAIN stage for instant additional saturation7 |
| Bypass | True bypass1 | True bypass7 |
| Current draw | 60 mA1 | 12 mA7 |
On the Bass model, the dedicated HIGH GAIN footswitch turns one setting into two performance-ready gain stages, so a player can step up saturation mid-song without bending down7.
Players and practical details
JAM Pedals lists Mick Thomson of Slipknot among the Red Muck's users, quoting him: "Red Muck will be my muff."1
"Red Muck will be my muff."
The maker offers a 30-day money-back guarantee with a no-questions-asked refund on return1. For UK orders the pedal ships free, DDP, with 20% UK VAT and all duties included, so there are no extra charges on delivery1.
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Questions
Is the JAM Red Muck true bypass?
Yes. JAM Pedals lists the Achenbach Red Muck and the Red Muck Bass as true bypass, so with the effect off the signal passes through without buffering. It runs on 9V DC with a center-negative plug, so it fits a standard pedalboard power supply.
How much current does the Red Muck draw?
The Achenbach Red Muck draws 60 mA at 9V DC, center-negative. The Red Muck Bass is a different circuit and draws much less, 12 mA. Both figures come from JAM Pedals' own product pages, so budget your power supply accordingly for whichever version you use.
Does the Achenbach Red Muck sound different from other Red Muck artwork versions?
No. JAM Pedals states that the custom artwork versions of the Red Muck mk.2, including the Achenbach, Feline, Lunar Muck, Noufaro, Relic and White Mountaintops, share the same sound and differ only in artwork. Each limited artwork pedal is a one-of-a-kind hand-painted piece, so the details vary from pedal to pedal.
What is the difference between symmetrical and asymmetrical clipping on the Red Muck?
A toggle on the Achenbach Red Muck selects between two clipping modes. Symmetrical clipping matches the Red Muck mk.1. Asymmetrical clipping gives a different response and harmonic texture, which to a player means a different feel and overtone character rather than simply more or less gain.
Sources (7)
- “Achenbach” Red Muck, JAM Pedals (jampedals.com)
- JAM Pedals Red Muck MK2 Fuzz, Delicious Audio, 2026-06-19
- “White Mountaintops” Red Muck mk.2, JAM Pedals (www.jampedals.com)
- "Lunar Muck" Red Muck mk.2, JAM Pedals (www.jampedals.com)
- “Noufaro” Red Muck mk.2, JAM Pedals (www.jampedals.com)
- "Feline" Red Muck mk.2, JAM Pedals (www.jampedals.com)
- “Achenbach” Red Muck Bass, JAM Pedals (jampedals.com)
