Catalinbread Karma Suture Review

Catalinbread Karma Suture

You’d think that the only thing that matters with guitar pedals is how they sound. And that definitely is one of the most critical elements — but other factors matter, too.  User experience (that relates to how the knobs and jacks are laid out and labeled) and expectation-setting (marketing, naming, pricing) play big roles in how players come to evaluate and appreciate guitar pedals.

In the case of Karma Suture, this pedal seems to be flying under the radar — overdrives and delays are the sexiest of pedals, and this pedal is a bit of a conundrum.  Is it a fuzz, overdrive or distortion?  Granted, there are other fuzz-based designs that have a similar marketing/branding challenge, but in the case of Karma Suture, one has to think about what the pedal actually offers to players.

As players, we don’t care as much about whether the pedal is a Tube Screamer variant or Rat descendant.  What we care about is the actual value, which is its sound and usefulness (the two are not synonymous), and learning about the lineage of the pedal’s design help us set the expectations of the value offered.  Karma Suture is fundamentally a fuzz pedal based on the mystical Harmonic Percolator.  I happen to be attracted to that idea, mostly because I have a weak spot for rarity/uniqueness and I also was familiar with another Percolator-based pedal, Barge Concepts BP-1.  But Harmonic Percolator isn’t a household name like Tube Screamer so I don’t imagine this pedal’s origins necessarily stir interests among guitarists.

I had known about this pedal but really didn’t learn the details until recently I stumbled across its description and the manufacturer’s excellent demo video.  Then I got excited and put it on my Wishlist at  Upon getting to know the pedal I got so excited that I had to purchase it.  It’s because it offered something I seek but don’t always find — dynamics, transparency, flexibility and uniqueness, all in one package.  This is no ordinary fuzz pedal.


The original Harmonic Percolator just had two controls, labeled “Harmonics” and “Balance.”  Huh??  That’s certainly a head-scratcher for us guitarists, so Catalinbread did seek to make the knobs slightly more descriptive, even still very un-intuitive.  The four knobs here are: Diodes, Density, Input and Output.

The Output knob is the only thing that immediately makes sense — it controls the overall volume.  Predictably, you can use this to boost your signal quite a bit.  Input essentially acts as the gain control — the more you turn up the more distorted the sound gets.   Those are the two knobs that exist on the original Harmonic Percolator.

Density and Diodes add welcome depth to this pedal’s range.  Density basically is pre-gain bass control.  Turn it up and the sound becomes fatter and muddier and more distorted.  Bass frequencies are the loudest, so the fuzzines kicks in the higher you turn up Density.  Keep it dialed out and you can stay in the overdrive range.   Finally, Diodes mix in additional diodes for clipping — so it affects the distortion and compression.  The higher you turn the Diodes up, the volume decreases and more compressed the pedal gets.  Both knob has a big range so they can really affect the sound.


Fuzz pedals come in all shapes, and while my experience with Fuzz Face based pedals has been that they can feel quite exaggerated in terms of dynamics — no sustain, attacks too loud, and so on.  This pedal gets the dynamics just right — with the Diodes at 10 o’clock or below the response feels very organic and natural, as if you are plugging straight into a tube amp.   With the Density at noon or below, the pedal is very transparent and its frequency range is extended from low to high, and the pedal has a startling amount of transparency, faithfully translating every nuance of the guitar’s sound and how the player plays it.  It rolls off the lows when you dial counter-clockwise, so you’ll want to do so as you turn up the Input/gain, if you want to stay in the overdrive range as you dial in more dirt.   Complex notes ring out clearly and the pedal displays a distinct chime — not really Vox-like, but chime nevertheless — particularly with a Strat’s in-between pickup position.

On the other end of the spectrum, you can turn up Density and make the pedal sound fat and ballsy.  The break-up character is definitely that of a fuzz when Density is set high enough, but the voice is not reminiscent of any other fuzz pedals — the lows take on synth-like attack, while raspiness and hair increase but somehow retaining sweetness and jangliness.  Note that this is not a high gain pedal — even with Input, Diodes and Density at max it will not do endless-sustain kind of gain.  Even at this extreme setting, the pedal retains some of its transparency, where you can still clearly make out the difference of pickup positions, and you can easily dial back the amount of dirt by rolling back the volume knob on your guitar.

Harmonic Percolators are said to emphasize even-order harmonics, and while I haven’t tried to scientifically verify this, it does sound like nothing I’ve heard before.  All settings retain a certain kind of sweetness and juiciness that cannot be made over-the-top harsh or abrasive.  It can be made to be muddy with Density turned up, but the highs are always retained so note definitions never get completely lost.  If you compare it to a more mid-heavy overdrive pedal, this can come across as scooped – if you’re looking for a cut-through-the-mix type voice you’ll have to look elsewhere.  Attacks are not hard or tightly defined, so this pedal won’t be great at single-note, hard-rock riff work.  On the other hand, it exhibits this psychedelic swirliness particularly with parallel pickup positions — the same quality that people often look for in Vox-like voices, but this pedal achieves the same effect but with a sound all its own.  The fuzzy break-up comes in before the gain becomes high enough to really act as a distortion pedal — so the main two tonal palettes this pedal offers are bright and responsive low-gain overdrive, or synthy fuzz.


If Karma Suture was touted as a dynamic low-gain overdrive, which it most definitely is, I feel like it would elicit more immediate excitement from guitarists.  There are many pedals that do just that and are well-received.  The fact that this pedal can do so much more, while retaining the simplicity of four-knob setup, makes this a much more desirable product than most other low-gainers on the market.  This pedal rivals the depth vs. simplicity balancing feats achieved by Lovepedal BBB and Trombetta Mini Bone — all three exhibit a wide musical palette of sounds while making it easy to dial them in.  And while those pedals deservedly command higher prices and hard-to-get availability, Karma Suture is affordable and widely available.  It’s simply waiting for you to grab it and help you set yourself apart from the rest of the crowd.

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