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Fuzzrocious Knob Jawn Review

Analog and digital octave effects meld, creating unique and complex octave tones.



Many unusual octave textures available via clever, blendable circuits. Rewards intuitive tone exploration.

Some traces of artifacts in digital-heavy blends.


Fuzzrocious Knob Jawn


Ease of Use:



Octave effects are clearly not everyone’s basket of biscuits. In fact, I’m always surprised by how loaded the topic of octave effects can be. “They sound like crap!” “Octave is cheesy!” “Is that *#@% thing broken?!?!?” Yeah, octave effects tend to engender, well … opinions.

But when you consider the giants and geniuses that have used octave effects to incredibly expressive and beautiful ends—Jimi Hendrix, Johnny Greenwood, Nels Cline, Jack White—you start to see a certain thread of fearlessness and creativity among their most fervent adopters. Perhaps all octave effects should come with a warning sticker: “Staunch traditionalists beware.”

Should such a law ever come to pass, Fuzzrocious’s Knob Jawn digital/analog octave will probably require this disclaimer. It’s bound to confound traditionalists and piss off tone snobs by the legion. But for just about anyone else that’s curious about stretching the electric guitar music envelope, Fuzzrocious’ blendable, digital/analog hybrid octave machine is a source of intrigue, thrills, and possibilities.

Bitchin’ Blend-o-Matic
Fuzzrocious says that, to their knowledge, the Knob Jawn is the only commercially available octave pedal with digital and analog octave circuits in the same enclosure. But even if that isn’t entirely the case, such a circuit is certainly rare. And it means you can coax some genuinely unusual textures from the Knob Jawn.

Not content to make the digital/analog octave equation an either/or proposition, Fuzzrocious instead made the two octave circuits blendable, which is where the giant knob that gives the pedal its name comes in. What are the differences between the two octave types? As it turns out, they’re pretty considerable. For starters, the digital octave effect can produce octave-up or octave-down tones. What’s more, those tones can be blended to create thick compound octave sounds. The taper and range in this control is nice, too. You can dial in very precise blends of up and down octave (although at low volumes, high-frequency signals will almost always seem more dominant at equivalent settings). You can tailor the output further using the wet/dry knob, which works with the digital side exclusively. And if all these possibilities still leave you wanting for ways to create drama and arresting sounds in performance, Fuzzrocious added an interesting second footswitch that inverts the high/low octave blend on the digital side.

The analog side is also very sensitive to guitar volume attenuation and tone adjustments, which can remove some of the more tin-foil-on-tooth-filling tones.

Inside, the Knob Jawn utilizes a compact, two-tiered circuit-board layout that makes room for footswitches and jacks to be mounted on the enclosure, independent of the board. The circuit itself is hand-populated on a through-hole board. And despite being fairly cluttered, the pedal looks rugged and completely serviceable in the event something goes wrong. It’s a smart, sturdy build.

Octave Impressions
The Knob Jawn’s two octave circuits not only differ in function. They also possess distinct and very different voices. The exclusively octave-up analog side has a clanging, metallic quality. But there are also hints of organic overtones that suggest koto or sitar. It’s surprisingly rich. And unlike many octave effects, the Knob Jawn sounds resonant and clear almost everywhere on the neck, and with neck and bridge pickups alike. The analog side is also sensitive to guitar volume attenuation and tone adjustments, which can soften the tin-foil-on-tooth-filling tones you hear with volume and tone all the way up, and create subdued, clearer-but-still-cutting octave textures.

As with any octave pedal, trying to fashion intelligible chords from anything more complex than a I-V construction usually yields a ring-modulated mess—at least at high guitar volume and tone levels. But strumming chords with lots of octaves and doubles, and using aggressively tone-attenuated neck pickup settings, produces unique, fuzzy, synth-pad like tones. Humbuckers are especially cool for these settings, and the massive, hollowbody Guild X-500 I happened to have around for this evaluation revealed how much extra mileage you can get by exploring disparate pickups and more resonant body types.

Digital octave sounds are much cleaner, and by themselves suggest classic digital octave effects like the Whammy. Depending on your tastes, such sounds may be intrinsically less appealing, but the real magic of the digital tones is how seamlessly they meld with the analog—adding definition to the fuzzier analog side, and clear, organ-pedal-like mass and throb when you add low-octave content.

When all three octave voices start working together, you can create scads of complex sounds. Settings that tuck a 50/50 mix of high and low digital octave just behind the analog octave are awesome for doubling lead lines to gargantuan effect. They can also generate unique electric 12-string alternatives when you want less dogmatic folk rock sounds or need a little more Martian in your McGuinn.

The Verdict
There’s a lot more to the Knob Jawn than meets the eye. The many blends you can coax from the pedal with casual, exploratory adjustments typically end up sounding genuinely musical—no mean feat for an octave effect. And with clever and resourceful application of guitar volume and tone attenuation, you broaden an already wide tone palette exponentially—a testament to the circuit’s sensitivity and unusually multifaceted and malleable personality.

Watch the First Look: