The JAM Pedals "Achenbach" Red Muck Bass is a bass fuzz/distortion pedal from Greek maker JAM Pedals, part of the company's hand-painted line. JAM Pedals describes it as "a full-bodied fuzz-distortion that brings Triangle and Red Army/Civil War Muff-inspired weight to bass without sacrificing definition"1. In other words, it takes the classic Big Muff fuzz voice and adapts it for bass, with a clean blend so your low end survives the fuzz.
The circuit draws on the '71 Triangle and later Red Army/Civil War Big Muff designs, adding what JAM Pedals calls a smoother response, stronger mids and fat lows1. Where a stock Muff can swallow a bass's fundamental, the Red Muck Bass is built to keep it in the mix.
A Muff-style bass fuzz with a clean blend
The Red Muck Bass sits in JAM Pedals' bass lineup alongside the Rattler Bass and Ripply Fall Bass. It is the bass version of the guitar-oriented Red Muck's family: the standard Red Muck mk.2 covers the same Triangle and Red Army/Civil War territory for guitar, and Delicious Audio has covered that Muff-style fuzz in its own writeup of the mk.22.
The feature that separates the Bass version from the guitar pedal is the clean blend. JAM Pedals says the Mix control "restores attack and fundamental exactly where you need it"1. For a bassist, that is the difference between a fuzz that sits on top of your dry tone and one that erases it: you dial in as much or as little of your untouched low end as the part needs.
The pedal also carries JAM Pedals' 30-day money-back guarantee, with a refund no questions asked if you return it within 30 days of receiving it1.
The controls
The Red Muck Bass has four knobs and two footswitches.
| Control | What it does |
|---|---|
| Level | Sets the output volume1 |
| Tone | Shapes the response1 |
| Gain | Controls fuzz intensity1 |
| Mix | Sets the ratio between dry bass and fuzz-distortion, preserving attack and low-end definition1 |
The right footswitch engages the main effect. The left footswitch engages a high-gain stage for instant additional saturation1, so you can set a base fuzz sound and step on the left switch for a thicker voice on a chorus or a solo. On the guitar version of the Red Muck, JAM Pedals describes this left-switch section as a separately tuned stage before the fuzz, with an internal trimmer setting its level, which can also work as a second high-gain stage when the main Gain is set lower3.
Circuit origins and artwork versions
The Red Muck name comes from its lineage: JAM Pedals says the circuit draws on the '71 Triangle Big Muff and the later Red Army/Civil War Muff designs1. The guitar version cites the same two influences, covering what JAM Pedals calls singing sustain, dense saturation and huge stoner-fuzz walls3. Guitarist David Torn is listed among the players of the guitar version3.
Like other JAM Pedals pedals, the "Achenbach" Red Muck Bass is a hand-painted piece, and the name refers to its artwork finish. JAM Pedals offers the same circuit in other custom artwork versions, including the "Brown" Red Muck Bass and the "Relic" Red Muck Bass, which the maker describes as "same sound, different artwork"1.
Every limited artwork pedal is a one-of-a-kind hand-painted piece. JAM Pedals states that the pedal you receive will differ in detail from the photos shown1.
The guitar Red Muck family carries the same arrangement, with custom artwork versions such as "Feline", "Lunar Muck", "Noufaro", "Relic" and "White Mountaintops" sharing one sound3.
Videos
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Riffs, Beards & Gear
BassTheWorld.com
Sources (3)
- “Achenbach” Red Muck Bass, JAM Pedals (jampedals.com)
- JAM Pedals Red Muck MK2 Fuzz, Delicious Audio, 2026-06-19
- “Achenbach” Red Muck, JAM Pedals (jampedals.com)
