JHS Fumble

The JHS Fumble is a true bypass JFET clean boost from JHS Pedals, a compact two-knob pedal that JHS says "creates a particularly enhanced clean tone"¹. It exists because of what JHS founder Josh Scott has called "the biggest mistake of my career": the clean boost side of the Notadümblë V1 DIY kit was accidentally built on the Dumble BBC-1 circuit rather than the intended one, and after fan demand for that wrong circuit, JHS released it in 2026 as the standalone Fumble²³.

JHS lays out four ways to use it: as a permanent buffer and clean boost at the front of your board, to slam the front of overdrives, to push a dirty amp harder, or as a solo boost at the end of the chain¹. Inside is an analog JFET preamp, and the pedal is assembled in Kansas City¹.

What it is and what it does

The Fumble is a boost pedal built around a JFET preamp, the same kind of transistor stage Alexander Dumble used inside his amplifiers, where he called it the FET mode³. JFETs (junction gate field-effect transistors) are favored in boost and overdrive circuits because they respond to input level in a way players often describe as tube-like; here the stage is run clean, adding volume and presence rather than distortion.

Because it is true bypass, the pedal passes your signal untouched when switched off, so it can sit anywhere on a board as a switched solo boost without loading your tone⁵. Left on at low settings it works as an always-on buffer and clean boost at the front of the chain¹.

JHS says the BBC-1 circuit it recreates is "a JFET preamp lifted almost part for part from a Barcus Berry acoustic preamp made in the 1970s"¹. Guitar World makes the same point about the BBC-1's origins, noting that it "isn't really a Dumble circuit at all"³.

The controls: Input and Output

The control set is two knobs, and it is unusual: instead of a single Level control, the Fumble splits gain shaping between an Input and an Output knob¹⁶⁴.

The Input knob is the interesting half. Rolling it back trims bass and gain together, which lets you thin the signal into the boost stage, a useful trick for tightening up a dark amp or keeping a bass-heavy guitar from flubbing when you push the front end hard. Output then sets how hard the boosted signal hits whatever comes next, whether that is an overdrive, an amp, or the rest of your board¹.

History: from the Dumble BBC-1 to the Notadümblë mix-up

The Fumble's story starts with the Notadümblë, a self-assembly Dumble-style pedal kit JHS released in 2025. The kit was meant to pair Dumble "violin lead tones" on one channel with an impression of John Mayer's A Box Later pedal for the clean side⁷⁸. Instead, the clean boost channel was accidentally built on the Dumble BBC-1, an ultra-rare, forgotten Dumble build⁷⁹.

Guitar Pedal X framed the release plainly: "JHS has released the BBC-1 Boost from its NOTADÜMBLË Drive as the standalone Fumble Mini Boost"¹⁰. Delicious Audio made the distinction between the two products clear for buyers: "if you want that BBC-1 preamp on its own, JHS released The Fumble earlier this month. $89. Fully assembled. Compact enclosure"¹¹.

The name itself is older than the pedal. JHS says the "Fumble" name and its football helmet icon had been "rolling around internally since April 10, 2012," originally planned for a Dumble-style overdrive that was eventually replaced by the Moonshine¹.

In the announcement video, Scott presents the Fumble as the standalone release of the circuit players had been asking for since the Notadümblë mix-up⁵⁷¹⁰.

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The Fumble and the DIY route

Players who would rather build the circuit themselves have options. The BBC-1 boost first reached the public as the boost side of the self-assembly Notadümblë kit, and PedalPCB sells a Fumble Boost PCB it describes as a variant of the "JHS NOTADÜMBLË / FUMBLE" circuit¹³¹. The JHS Fumble itself is the fully assembled route: standalone, compact, no soldering required⁶.

What reviewers said

Pedal of the Day reviewed the Fumble on July 16, 2026, and found a lot of range in a small box⁴:

The same review noted the pedal takes up little pedalboard space while delivering what it described as a particularly enhanced clean tone⁴. Gearnews highlighted the JFET preamp inside, saying it "imparts just the right amount of warmth, dynamics, and transparency to the signal," and confirmed that the true bypass switching leaves the original signal completely unaffected when the pedal is off⁵. MusicRadar pointed to the price as part of the appeal, noting "it is only $89"².

Videos

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Questions