The Motherload Holy Grail Distortion Muff-Rat is a compact distortion pedal from the Greek maker Crazy Tube Circuits Motherload that puts two classic gain circuits in one box: a Rat-style distortion and a Big Muff-style fuzz. Guitar Pedal X's Stefan Karlsson, writing in his 2024 roundup of compact Rat-style pedals, described it as "A really smart dual-circuit - where you can combine the two tone stacks together"1.
What it does
A Circuit switch selects between the Rat and Muff sides of the pedal, and the design lets the two tone stacks work together rather than forcing an either-or choice. Each side carries its own voicing controls: the Muff side gets a Tone control and a Voice control for mids, while the Rat side gets a Filter control that works as a hi-cut. A set of Link EQ buttons combines all three EQ controls into one mode1.
| Control | What it does |
|---|---|
| Volume | Output level |
| Circuit | Selects Rat or Muff |
| Gain | Amount of distortion |
| Tone | Muff-side tone |
| Voice | Muff-side mids |
| Filter | Rat-side hi-cut |
| Link EQ buttons | Combine all 3 EQ controls |
Karlsson's verdict on the combined mode was positive: "The Rat with all 3 EQ's combined sounds quite superb."1
For players weighing it against single-circuit Rat-style pedals, the Motherload's distinguishing feature is that combinable EQ architecture: rather than choosing one circuit's tone stack, the Link EQ mode brings all three EQ controls to bear at once1.
Price
Guitar Pedal X listed the pedal at €249 / $279 / £211 in its 30 August 2024 buying guide1. The guide gave prices in three currencies without ruling one as the definitive list price.
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Questions
What does the Motherload Holy Grail Distortion Muff-Rat do?
It is a dual-circuit distortion pedal that pairs a Rat-style distortion circuit with a Big Muff-style fuzz circuit. A Circuit switch selects between the two, and the pedal's design lets you combine the two tone stacks together, with a Link EQ feature that ties all three EQ controls into one combined mode.
How much does the Motherload Holy Grail Distortion Muff-Rat cost?
Guitar Pedal X's 2024 buying guide listed the pedal at €249 / $279 / £211. The listing gave prices in euros, US dollars and British pounds, and no single currency was ruled the definitive list price.
Sources (1)
- Guitar Pedal X, Guitar Pedal X, 2024-08-30
