The Whimsy Machines Jeff V2 is a fuzz pedal built around a custom JFET take on the Big Muff circuit. The name says it plainly: Jeff stands for JFET plus Muff, because instead of the transistor arrangements used in the various historical Big Muff versions, Whimsy Machines built its fuzz from JFETs. Delicious Audio's builder's notes describe it as "our 100% custom JFET based Big Muff (Jeff = JFET + Muff)"1.
It is the second pedal to carry the Jeff name, following the first Jeff release, and it was covered by Delicious Audio in June 20221. Whimsy Machines also makes other unconventional effects, such as The Great Fantabulizing Whatsitdo.
A Big Muff-based fuzz that goes its own way
The Big Muff is the most fuzzed-over circuit in pedals, and most pedals inspired by it stay close to home. The Jeff V2 does not. Where the first Jeff, in the builder's words, "strived to respect the paradigm of the original Big Muff" while still designing "what a Big Muff could be," the V2 heads somewhere else entirely. Delicious Audio quotes the builder: "This version respects no paradigm and was made to befuddle the tone chaser. Without hyperbole, this is for those that tr[uly] want something different"1.
The builder also says this new version "develops the circuit in creative directions unknown to any of the original Big Muffs"1. For a player, that means the Jeff V2 is a Big Muff-derived fuzz in lineage but not in behavior: the core is familiar, and the EQ section and toggles take it well past what any original Big Muff could do.
For context, the Big Muff family itself is still being extended by Electro-Harmonix, with recent entries like the Big Muff 2, which Guitar.com's reviewer called "a straightforward fuzz with a powerfully throaty sound"2, and the JHS collaboration Electro-Harmonix by JHS Big Muff 2, whose Sustain control "controls the amount of fuzz, which increases the sustain when turned up"3. The Jeff V2 sits in that same family tree of Muff-derived fuzz, but at the experimental end of it. See Fuzz Pedals for where it lands among fuzz types.
The controls and toggles
The Jeff V2's most distinctive feature is its EQ. Rather than the tone control of a conventional Big Muff, it carries what the builder calls "a rather peculiar EQ section": a two-stage gyrator-based EQ with cut and boost for lows, cut and boost for highs, and a sweepable mid frequency boost1. A gyrator EQ uses active circuitry to shape specific frequency bands, which is how the pedal can both cut and boost each band instead of a passive tone control's cut-only behavior.
The center three knobs are "regular" Low and High knobs plus a Sweep control1:
| Control | What it does |
|---|---|
| Low | Cut/boost of the low band, part of the two-stage gyrator EQ1 |
| High | Cut/boost of the high band, part of the two-stage gyrator EQ1 |
| Sweep | Boosts a middle frequency of choice1 |
| Clipping Boost toggle | Activates a clipping stage high-frequency boost1 |
| Oscillate Enable toggle | Turns on a pre-amp stage oscillation that will facilitate feedback1 |
The two toggles are where the V2 leaves Muff territory. The Clipping Boost lifts the high frequencies in the clipping stage, and Oscillate Enable lets the pre-amp stage run into oscillation, which the builder says "will facilitate feedback"1. That is a control no original Big Muff offered, and it is the kind of feature that gives the pedal its experimental character.
From the first Jeff to Jeff V2
The Jeff V2 is the second incarnation of the Whimsy Machines Jeff1. The first Jeff aimed to respect the paradigm of the original Big Muff while still asking what a Big Muff could be; the V2 drops that restraint and develops the circuit in directions the builder says are unknown to any of the original Big Muffs1. Players who found the first Jeff too polite have in the V2 the version built to be strange.
Whimsy Machines is a small builder working in the same oddball space as other niche makers; for a very different kind of effect from a small company, see the FOMOfx Virtual Jeff Wammy, a pitch shifter, octaver and harmonizer4. Whimsy Machines describes the Jeff V2 itself as a pedal that "respects no paradigm and was made to befuddle the tone chaser," aimed at players who truly want something different1.
Questions
Is the Whimsy Machines Jeff V2 based on a Big Muff?
Yes. Delicious Audio's builder's notes describe the Jeff V2 as a 100 percent custom JFET-based Big Muff, with the name Jeff standing for JFET plus Muff. The builder says this second version develops the circuit in creative directions unknown to any of the original Big Muffs, so it is a starting point rather than a straight clone.
What does the Oscillate Enable toggle do on the Jeff V2?
The Oscillate Enable toggle turns on a pre-amp stage oscillation that will facilitate feedback. In practice it lets the pedal's internal pre-amp stage run away into oscillation, which players can use to push the fuzz into self-generated feedback and sustain.
What does the Sweep knob do?
The Sweep control boosts a middle frequency of choice. It is part of a two-stage gyrator-based EQ that also offers cut and boost for lows and highs, so the Sweep knob lets you pick which midrange area gets lifted.
What kind of transistors does the Jeff V2 use?
The Jeff V2 uses JFETs. Whimsy Machines describes it as a 100 percent custom JFET-based Big Muff, and the name itself is a contraction of JFET and Muff.
Sources (4)
- New Pedal: Whimsy Machines Jeff V2 Fuzz, Delicious Audio, 2022-06-09
- EHX Big Muff 2 review, Guitar.com, 2026-05-15
- EHX BY JHS, JHS Pedals
- Virtual Jeff Wammy by FOMOfx, RockBoard PedalPedia, 2026
