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Black Cat Monster K-Fuzz Review

A menacing and expressive octave fuzz classic is recast in a more practical and musically malleable form.

My first real exposure to the original Kay Fuzz came via Daniel Lanois’ soundtrack to the film Sling Blade. I was used to Lanois being resourceful, unbridled, and emotional in his playing. But there was something in the harrowing track “Orange Kay” that added menace to Lanois’ already emotive attack. The monster in the mix, so to speak, was the fuzz pedal that gave the track its name. And though I’ve tried to use octave-up pedals to approximate the textures Lanois conjured in “Orange Kay,” nothing quite delivered the frantic, time-ripping-at-its-seams, desperation that Lanois’ Kay Fuzz and it’s treadle-activated filtering evoked.

Black Cat Pedals’ Tom Hughes was one of the first to nail the Kay Fuzz sound and functionality when he built a clone into a standard wah enclosure. But the first-generation Monster K-Fuzz (as he called it) was very limited and expensive. Now the Monster K-Fuzz has returned. And while you’ll need to use or invest in an expression pedal to get true Kay Fuzz-style performance, the latest version also comes with new clipping, voicing, and gain features that broaden its usability and enable the pedal to work with a wide range of guitars, amps, and other stomps. This could be the most versatile Kay Fuzz-inspired pedal ever.

The Monster K will deliver full-spectrum grind without collapsing under its own weight.

The Citrus Avenger
While there are many similarities in the basic circuitry of Monster K and octave-up fuzz pedals like the Shin-Ei Super Fuzz and Foxx Tone Machine, there are pronounced differences in tone and dynamics. One of the primary differences is that the Monster K is much smoother, less clipped, and less likely to glitch out in the high-mid range at most settings. That makes the Monster K well suited for the tone-shifting, volume swell-like effects you can extract with an expression pedal. The shift or curve of the fuzz frequency can feel relatively steep and abrupt when using an expression pedal. (I used a Moog EP-3.) But it’s not binary, on/off attenuation either, and if the contour isn’t exactly an elegant arc, the output still shifts smoothly. (This fast, steep filtering curve is probably most famously used on the Edge’s intro to U2’s “Elevation”).

The Monster K’s smoother nature means it’s easier to bend and hold notes aggressively with less of the high-mid sputtering some octave pedals generate—at least if you keep the fuzz frequency in zones that favor high-end content. The sustain at these settings is also impressive and unusual—even with small amps, which tend to crap out more easily under the assault of an octave pedal’s harmonic tangle. Sustain is especially pronounced when you use your neck pickup and pick notes above the 9th fret, where high octave notes bloom and shine more clearly. The pedal’s ability to sustain and provide greater harmonic order does wonders for power chords, too. Want to add a ripping high-mid overdub texture to a rhythm guitar part, or create brash counterpoint to a driving bass arrangement? The Monster K will deliver full-spectrum grind without collapsing under its own weight.


Dazzlingly smooth, dynamic, and expressive octave fuzz voice. Useful, mix-and-match clipping and voice modes.

Requires expression pedal to get the most authentic Kay Fuzz effects.


Ease of Use:




Black Cat Pedals Monster K-Fuzz

If you do like the glitchiness and unpredictability of octave-up pedals, the Monster K will do that, too. The key is to pinpoint—or transition through—the fuzz frequency settings where the high and high-mid content is filtered more aggressively than the low-end output. The result is a harmonic profile in which low-end notes sustain with ominous, fuzzy weight while high-end signals dart, rise, and plummet like a scattering flock of shrieking birds. And while you can create this effect by parking the fuzz frequency knob in the right place relative to the output from your guitar, amp, and other pedals, the most eloquent way is to navigate around that point with an expression pedal.

Another way to affect the dynamics of the Monster K-Fuzz is through use of the input gain control. While the effect can be subtle and comes in handy for switching between guitars of varying outputs, it can also alter the feel of the frequency sweeps and pick attack, lending an almost compressed quality at maximum settings that’s not unlike hitting the front end of a spongy Fender tweed amp with a fuzz. It’s a killer way to add soft-edged chaos in the low-end of the frequency spectrum, and more unhinged, but still very lyrical, output.

The voice and clipping settings, which are unique to the Monster K, also have a profound effect on the output, but in a welcome and surprising way that doesn’t alter the basic dynamic feel as much as you might imagine. Instead these modes tend to add or reduce headroom and volume without dramatically transforming the personality of the pedal. The differences in decibel ceiling can be extreme. I loved the warm glow and softer edges of the germanium diode setting mixed with the vintage-voicing mode, which together approximate the sound of the original Kay Fuzz. The silicon clipping diode worked well with vintage and stock voicing modes, too—adding extra cut and definition that’s fine in a loud band setting. Using the ‘”Schottky” diode settings and the monster voice, however, makes the Monster K ridiculously loud and a little less harmonically complex and dynamic—though very capable of rising above the loudest band.

The Verdict

Black Cat’s Monster K-Fuzz is an agreeable, adaptable, capable, and unique octave fuzz. The many clipping and voice modes make it easy to coax the pedal’s softest contours or rise above the loudest mix. But it’s the basic voice and personality of the Monster K—a cool, expressive, smooth, and always-verging-on-explosive edginess—that makes it intriguing and intoxicating. And while it’s a shame that the pedal doesn’t come in an all-in-one, treadle-based design like the original Kay Fuzz, the simple and relatively minor investment in an expression pedal should not be a deterrent from investigating the wilder frontiers of fuzz this pedal puts at your fingertips.

Watch the Review Demo:

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