• Spark Gap Kontakt instrument front panel UI
  • Spark Gap Kontakt synth rear panel UI

Spark Gap

(25 customer reviews)

20.00 plus VAT

Experimental 1920s voltage-driven perpetual resonator


“Kontakt instruments don’t get much more esoteric than this… Spark Gap sounds hauntingly beautiful and just very cool”Computer Music magazine

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“Spark Gap continues RR’s honourable tradition of finding beauty in the old and the knackered… In common with all the RR instruments I’ve encountered so far, the sampling is clear, impeccable and 24‑bit; just what’s needed to reproduce noisy, nasty technology from the dark ages!” – Sound on Sound magazine

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“Spark Gap is so creative and unique. I found myself writing with it as soon as I started the review. So many possibilities from such an interesting sample set. I don’t know what wavelength The Professor surfs on, but I just became a Rhythmic Robot fan.” – SampleLibraryReview.com


Electrical fork 1The source tones for Spark Gap come from a wonderful piece of scientific history: a vintage 1920s electrically-driven (or “maintained”) tuning fork. This bit of lab kit comprises a hefty brass fork bolted to a resonant box and fitted with a moveable pair of damping clamps plus a moveable electromagnet, and was used nearly a century ago to demonstrate the principle of the electromagnetic feedback loop. But while it may have been designed for the edification of young scientists, it’s first and foremost a sound-producing machine – which made it pretty much irresistible to us…

The “maintained fork” is an elegantly simple bit of kit. The magnet – the thick black disc – sits between the fork’s tines, dormant until current passes through it. That current is supplied via a pair of make-or-break contacts, one of which is attached to one of the two steel damping clamps (and so is effectively attached to the fork itself). The other is independently clamped. When they touch – or spark, which they do a lot – current passes instantly to the electromagnet, which becomes magnetic, and attracts the two steel damping clamps… thereby dragging one of the two make-or-break contacts away from the other, and breaking the circuit. The moment that happens, the current stops flowing; the electromagnet shuts off; the tines spring back; the contacts reconnect; the current starts flowing; the magnet switches on… and the process continues like that indefinitely, being “maintained” by the electrical current and the mechanical feedback loop, yielding a loud and theoretically stable tone which can be varied in pitch by adjusting the position of the electromagnet, clamps, and sparking contacts.

Basically, once you set it going, it never stops. Which is kind of cool. But what’s even more cool is that it sparks, crackles, makes bits of smoke, and at one point when we were sampling it, welded itself to itself and shorted out the circuit-breakers in our lab-grade power supply. That was really cool, and smelt nice, too.

Spark Gap rear panelFeed the fork enough DC current, and “tune” it with an arcane series of adjustments to its mechanics, the size of the spark gap between the make-or-break contacts, and the precise voltage of the power supply (it’s picky… most of the time it seems to like about 4v, but once we had to feed it 12), and you get an astonishing raw, rattly, crackling, sparking sound just begging to be played polyphonically. Where a conventional tuning fork produces as near as makes no odds a pure sine wave, this amazing laboratory antique is nowhere near as polite: its constantly drifting, buzzing, resonating pulse sometimes takes in strange overtones, sometimes gets contaminated with mechanical rattlings as screws shake loose, and is constantly – but erratically – reinforced by the sound of the spark gap arcing. In fact, we were so taken with those little background crackles that we decided to call the instrument “Spark Gap” in their honour.

Spark Gap comes with a set of controls carefully chosen to complement its vintage nature. A standard ADSR envelope allows you to sculpt your tone, while the Sine knob controls the level of a pure sine wave which can be added to the tuning fork tone to reinforce its fundamental. High- and Low-pass filters affect the fork tone only, allowing you to craft this and then blend it with the Sine; this gives access to a very wide range of musically usable sounds, as you can go for a full-on vintage crustiness (by dialling back the Sine and leaving the filters off) or get a very subtle degree of crackle into an otherwise well-behaved wave (by, say, using the Sine as the main oscillator and severely high-pass filtering the tuning fork tone so that just a hint of it comes through).

Electrical fork 3The Key Off knob adjusts the level of a random pool of buzzes, thumps, crackles and chirps which the fork makes when manually damped: these play when you release a note and add considerably to the charm of the sound. By combining a slow-ish attack with a medium-level Key Off setting, you can get a convincing “bowed” sound not a million miles off an E-Bow guitar tone – if electric guitars and E-Bows had been invented in the 1920s.

Round the back there are controls for stereo Delay and Reverb, both of which are great for thickening the sound or adding sonic breadth. There’s also a simple Output switch, which ropes in convolved impulse responses of a studio condenser mic and a vintage-style graphite mic to give a subtle but pleasant extra dimension to the sound.

Spark Gap excels at conjuring up visions of the past. It’s an eerie, sometimes spooky sound which wouldn’t be out of place in a grainy black-and-white horror movie. It also lends itself naturally to sound design, producing washes and soundscapes with a unique “bite” of crackle and tension. Perhaps best of all, you don’t have to deal with the possibility of it shorting out your studio and setting fire to your microphones.

(All our Kontakt instruments require a full copy of Native Instruments Kontakt v4.2.3 or higher (including all versions of Kontakt 5). Kontakt Player is not supported: instruments will load, but will time out after 15 minutes. See the FAQ for further information.)

25 reviews for Spark Gap

  1. Lee (verified owner)

    At first, I had a difficult time finding a use for this one. But once to try it and it fits on a track, you realize why you need it. Great texture.

  2. Poesque (verified owner)

    Intermittent sonic bliss interrupted by the space that defines time.

  3. aqaraza (verified owner)

    I Despite wishing to all heaven that this had a glitch button, I simply could not resist its subtle charms. Then, once I started playing with it, I realized that a glitch button would not necessarily result in massive variation with this instrument: It has a distinct voice, and operates within that realm. Its sound, though, is so unique and unplaceable (if you don’t know what it is). It is fragile, ragged, resolute, fearless, exposed, raw, subtle, and primordial. It does one thing, but that one thing is amazing.

  4. michael.topic (verified owner)

    This is another one of those instruments that intrigues, rather than bludgeons the listener. You think you’re hearing something unadorned and simple, but there’s something going on that you are compelled to try to figure out with your brain. I love sounds like that. They are deceptive, but very noticeable. It’s the subtleties that absolutely make this one, for me. When the Fairlight CMI came out, there was a sound sampled from a very breathy singer (called Sarah) and that sound finished up on everything, because you just couldn’t ignore it. I think the sounds in Spark Gap have a bit of the same thing going on. You want to hear more. The more you hear, the more you anticipate.

  5. Monika Edvardsen (verified owner)

    This is so cool! It sounds a bit like a big, bowed wineglass, but with its own kind of grit. With only a few samples and no round robins you’d expect it to sound static, but it’s got random sample starts and LONG samples (+random note offs), so it sounds very alive indeed. Sounds good on its own, but also very cool when you add Rotator, Chorus or Phaser/Flanger.

  6. pbrmei (verified owner)

    Spark Gap produces beautiful sounds with as much noises you want it to generate. I first thought it would be a one-trick-pony, but its very simple controls allow to shape the sound in lots of very useful ways that makes it a lot more versatile than it looks. Great work RR!

  7. DON Chaffer (verified owner)

    This is all about overtones. Noise overtones, and it’s not vinyl, and it’s not tape hiss, it’s… what is that exactly? That’s what people will ask you. And these days, getting that question is what you want. Spark gap. I’m in.

  8. Stefano (verified owner)

    Spark Gap has an eerie and original character. Is fantastic when you play chords, and playing single notes remind me a rusty musical saw with a steampunk mechanism!

  9. Chris (verified owner)

    It clicks, sparks, screeches and seems to be alive! Spark Gap is not going to work every time you reach for it, but when it does work, it’s magical! I use it for unusual keys textures with a unique lo-fi vibe.

  10. Joe (verified owner)

    Beautiful. It’s the perfect balance of sweetness and tooth-jarring texture: wonderfully musical and utterly charming. It speaks of Bagpuss and the sea.

  11. Simon (verified owner)

    I really like this little guy. I’ll mix it in with sample-based orchestra strings, and suddenly there’s a whole lot more character…. or throw it in with a bunch of waterphone samples for an instant horror score. It does what I want my Rhythmic Robot synths to do: get my sound “out of the box.”

  12. Dee (verified owner)

    Beautifully weird.. just the way I like it. A nice addition to my Rhythmic Robot collection. This website is like a toy shop… so many unique and attractive instruments… great friendly service too… thank you RR ♡ ☯ ☆ ☮ ♫ ☢

  13. Steven (verified owner)

    This is such a cool instrument to add unusual sounding textures to you music. It is the opposite of sterile!

  14. Alexandre (verified owner)

    Easy to play with, if you search an instrument to explore new sound, Spark Gap is the one. Open your ears !

  15. Pablo (verified owner)

    Beautiful textures with unique personality, this instrument is great for experimentation and some unexpected colors!

  16. Gerard (verified owner)

    Yet another Spark of inspiration from Rhythmic Robot!

    Aside from ambient pads and chords, I’ve found that this can make a really good lead! Sure, it doesn’t growl or scream, but something about the timbre works great with eerier melodies.

    Simple, yes. But perhaps that’s the beauty of it.

  17. Martin

    Very lovely and delicate sound. When you’re about to reach for a violin patch, try reaching for this instead.

  18. johnny

    An outstanding sound, and a very inspirating instrument. Spark Gap, like others amazing RR stuff, can bring some real vintage and intriguing feels to your circus or steampunk compositions. I use it a lot for a side project called Lant3rn, and at this price, I warmly recommend it. A must-have for cinematics or sound designers in my opinion…

  19. Matthias

    this is the most weird instrument created by RR … check it out if you are into something bizarre … a hidden gem

  20. Andrzej

    Great price and also great dusty sound. Very helpfull to achieve steampunk sound, it could works as legato stings for pieces which reqiure somethings unusual.

  21. Edward Ka-Spel

    When I heard that Rhythmic Robot had created a Kontakt Instrument based on an old tuning fork I was left scratching my head. Wouldn’t this be impossibly limited? Could this be hard cash invested in an admittedly handsome pony that knew just one trick? The answer was a firm “NO”. “Spark” encourages you to get under the hood of Kontakt and tinker…and ,as a result, it even helps you to understand that complicated sampler a little more. I love “Spark Gap”…been creating a series of “Sparkscapes” which will play a part in the admittedly esoteric albums I plan to release over the next year.Addictive. Edward Ka-Spel

  22. Garry (verified owner)

    Instantly inspiring instrument that excels as a focal point for ambient music. It’s also excellent as an additional instrument for other genres of music if you have an open mind for such a timbre. Lately, it’s been a go-to plugin for an experimental hip-hop project I’m working on. Highly recommended for those open to unusual and quirky tones/timbres.

  23. Robert (verified owner)

    If you’re looking for something really different, something to literally spark your creativity, this is the instrument for you. I cannot explain it with words you
    have to experience it. I think of it as a fine spice used just right it will ad flavor to your next creative endeavor.

  24. Theo

    You might find yourself asking if you need an instrument that only really does one, rather odd thing… and no, you don’t NEED it. But if you’re doing any sort of sound design or other weirdness, it’ll worm it’s way into that pile of go-to patches simply because that one thing is very, very useful, and very well realised. In a word, characterful.

  25. Graham

    Spark Gap has really inspired recent work for me. I can’t praise this value-for-money instrument more highly. Easily one of my favorite Kontakt instruments ever. So quirky, lo-fi, beautiful and most importantly; unique.
    Probably not for fans of epic Lord of the Rings style soundtracks, more suited to fans of early Sigur Ros…if that makes sense (?).
    In world of endless grand piano and symphonic instruments, Rhythmic Robot keep making things like this which set them apart from many other producers. Oh, and Shortwave is amazing too.

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