Compact, affordable Uni-Vibe-inspired pedals have become abundant in recent years—an excellent development for psychedelically aligned modulation fiends like this editor. What makes this proliferation of swirl machines extra-cool is that builders are also looking beyond mimicking the original Uni-Vibe (a thankless task for digital engineers in particular), adding extra features and sounds that expand on the original’s possibilities.

At its core, TC Electronic’s $129 Viscous Vibe is a digital-modulation machine for Vibe fans on a budget. For plug-and-play types it delivers a fundamentally Uni-Vibe-like voice colored by a low-end-heavy, tremolo-like intensity. But Viscous Vibe also incorporates TC’s Tone Print technology, making many more flavors available via download. While many of these extra textures aren’t authentically Uni-Vibe-like, they make the Viscous Vibe a formidable and versatile modulation unit.

Green Waves
The Viscous Vibe comes in TC’s signature Tone Print pedal enclosure. It features the same basic controls as a Uni-Vibe: A small switch toggles between the commonly used “chorus” effect and the 100%-wet vibrato function. (Its middle position activates downloaded Tone Print voices—more on this in a bit). Three knobs control effect intensity, volume, and modulation speed.

The more radical Tone Prints have little to do with replicating vintage Uni-Vibe tones, but they greatly expand the pedal’s range for experimentally minded players.

The speed control is a large knob you can probably operate with your foot if your pedalboard isn’t too crowded. Holding down the footswitch activates a ramp-up sweep. The big knob and ramp-up function are game attempts to capture the functionality of the original Uni-Vibe’s pedal-controlled rate setting, though neither can match the pedal’s expressive potential.

Opening the pedal (by twisting a single, substantial screw with a coin) reveals little—a removable protective hood covers the IC. But you’ll see DIP switches for true-bypass/buffered switching and a kill-dry function that mutes the direct signal when using the pedal in an effect loop. There’s also a 9V battery compartment. On the exterior are a 9V DC jack and the USB 2.0 port used to download Tone Prints. Like all pedals in this series, the Viscous Vibe feels rock-solid.

Smorgasbord Of Swirl
In chorus mode, the Viscous Vibe’s bass-heavy coloration can be both virtuous and problematic, depending on your style and rig. With bridge single-coils and hot humbuckers, it can sound throaty, vowely, heavy, and huge, especially for chords, arpeggios, and slow, liquid solo passages. It can also be a killer companion for an unruly fuzz. My buzzy, hot, and spiky silicon Fuzzrite clone sounded much more substantial, and the fuzz’s extra highs helped animate the modulation sweeps.

Ratings

Pros:
Versatile modulation. Flexible Tone print functionality. Sturdy. Rich basic tone.

Cons:
Default chorus voice can have too much low-end emphasis for humbuckers and bass-heavy amplifiers.

Tones:

Ease of Use:

Build/Design:

Value:

Street:
$129.99

TC Electronic Viscous Vibe
tcelectronic.com

There are drawbacks to that ample low end. The relative lack of high-mids means sweeps can sometimes have an on/off, almost tremolo-like quality. This can be a killer effect for chord riffs, but some players may miss the original Uni-Vibe’s smoother harmonic curve.

But if the default chorus voice doesn’t suit your rig, more options are available among the Tone Prints (which are easy to access and great fun to experiment with, regardless of your needs). The “Vintage Vibe” download seemed to smooth and de-emphasize the low-end content that made the default chorus setting a poor match for my Fender Bassman. Other downloads are less conventional: “Space Vibe” adds a flanging effect whose intense sweeps move in subdivisions parallel to the Vibe modulations. “Thirsty Hearts” adds Tri-Chorus with similarly intense and disorienting results. Clearly, the more radical Tone Prints have little to do with replicating vintage Uni-Vibe tones, but they greatly expand the pedal’s range for experimentally minded players.

Vibrato mode (widely underutilized on vintage Uni-Vibes) adds another cool dimension. While not as versatile or intense as TC’s own Shaker, it’s more organically queasy and animated than some digital vibratos I’ve encountered—a damn good thing in my book. Slower vibrato speeds are particularly effective, especially with buzzing ‘60s-style fuzz.

The Verdict
Duplicating the smooth contours of an original optical Uni-Vibe circuit is tough, especially in the digital realm. While the Vicious Vibe doesn’t precisely capture the depth and harmonic complexity of a good optical unit, its Tone Prints make it far more flexible than the original, especially if you want to move beyond well trodden and hard-to-top Hendrix moves. Built tough and sensibly priced, the Viscous Vibe is an appealing and affordable chorus/vibrato option.

Watch the Review Demo: