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Strymon UltraViolet Review

Strymon UltraViolet pedal review

Uni-Vibe sounds and beyond!

Intoxicating, addictive, and ultra-elastic Uni-Vibe, phase, chorus, and tremolo sounds—many that sound super unique. Great range in controls. High quality.

No capacity for onboard presets.


Strymon UltraViolet


Modulation effects are an enduring source of new hooks and riffs. But while I hear loads of vibrato, tasty tremolo, and chorus in a lot of contemporary guitar music, I don’t encounter much in the way of Uni-Vibe-style tones. I guess I can understand why. Used unimaginatively, Uni-Vibe sounds probably seem a bit loaded—inextricably bound up in the heavy psych swirl of Hendrix and Pink Floyd.

Remove those contexts and preconceptions, though, and a Uni-Vibe-style effect can surprise—particularly when it takes advantage of digital processing to stretch the Uni-Vibe envelope. Strymon’s new UltraViolet gracefully uses the DSP advantage to expand the Uni-Vibe template’s potential—conjuring swimming-in-bubblegum swirl that feels authentically analog and can dwell comfortably in sound spheres outside the psych-rock canon.

Streamlined Straight Line to Psycho Swish

Even at their most complex, Strymon pedals are cool studies in approachable digital pedal design. More recently, though, Strymon started dabbling in more compact, streamlined stomps. Used here, that design philosophy gives the UltraViolet a fluid functionality suited to its rich, gooey voice.

There are modulation stars elsewhere in the Strymon line. The multi-modulating Mobius and the yummy harmonic tremolo on the popular Flint tremolo and reverb are each marked by a beautiful, perceptible depth in the modulations. That complexity is very evident in the UltraViolet, and its elegant control array makes it fun to explore those intricacies.

The sensitivity and interactivity in the most basic controls—speed, intensity, and volume (which puts up to 4 dB of boost at your disposal)—create a rich palette of possible sounds. Strymon made cool tweaks to these controls, too. Specifically, they increased the range of the intensity control relative to a real Uni-Vibe, making it capable of more intense modulations at slow speeds. The tweak may be less than authentic, but it results in thick, super-dreamy slow-phase sounds that lesser Uni-Vibe-style stomps, and the real thing, don’t deliver.

The real treats, though, are the blend mode, which offers a 70 percent/30 percent dry/wet mix, and the bias mode switch which shifts frequency emphasis in the modulations. The blend mode is a more articulate and sometimes smoother alternative to the chorus and vibrato channels. The 3-position bias switch, meanwhile, can completely recast the sound, feel, and response of a given modulation setting as well as change the interactive dynamics of the controls. Together, they make the UltraViolet’s vocabulary expansive. All those tone variations can leave you longing for presets, which the Ultraviolet accommodates via MIDI (up to 300 presets) or the optional MultiSwitch Plus. Unfortunately, there’s no way to access presets in the absence of these methods. That limitation makes the UltraViolet no less fun, though.

Wiggle Room for Weirder Wobbles

If you’re used to more basic Uni-Vibe style pedals, the range in the Strymon’s controls can feel tricky in the courting stage. They’re sensitive, and small shifts can reshape a modulation pattern profoundly. But it’s also really fun to dive in blindly and not get too surgical. Along the way, you’re likely to discover that the UltraViolet is capable of subtlety at low intensity levels, enabling you to background radical textures—fast-fluttering modulations, for instance—that lend kinetics and mystery to a song without overpowering it. You’ll also find elastic sounds with beautiful vowelly overtones that warp and stretch simple chord patterns into deeply immersive environments.

The very cool bias switch transforms these already alluringly chewy modulations. Low bias mode tends to emphasize throbbiness—lending many faster rate settings a delicious harmonic-tremolo-like pulse. At slower, phasey rates, it will coax elongated “wow”overtones from slo-mo’ waveforms, giving spare phrases weight and soulful character. The low-bias mode can be overpowering. But more unhinged, psychedelically minded players may well relish the extreme pulses found here. The mid-bias mode is, to my ear, the least appealing of the bunch. The mid-forward EQ profile tends to obscure richness and detail in the waveforms. But this could be an advantage for players that want to foreground fuzzy leads or intricate rhythms. The high-bias mode is the most traditional of the bunch—silky, smooth, with a just-right rubberiness that will please Uni-Vibe traditionalists as well as vintage analog phaser fans.

These same characteristics are apparent in the blend mode, but there is more room for picking dynamics, finger-vibrato nuance, and rhythmic thrust. It’s a cool compromise for Uni-Vibe and phaser skeptics, and it extends the utility and value of the pedal significantly. Some people consider a real Uni-Vibe’s vibrato useless. I always found that assessment harsh. Certainly, it doesn’t have the caramel gooiness of the chorus mode. But here it can be made much more interesting and easier to tailor to a specific musical context with help from the bias mode switch.

The Verdict

The quality and variety of sounds, as well as the fun, intuitive means by which you can explore and manipulate them, make the high-quality, U.S.-made UltraViolet look like a relative bargain at $259. For some players, the lack of onboard preset capability might make that price less appealing and make the pedal less practical for the stage. For just about anyone else on the prowl for authentic Uni-Vibe sounds—and that relishes the chance to shape them into more unique textures—the UltraViolet has the potential to be a most intoxicating pedalboard asset.