Premier Guitar features affiliate links to help support our content. We may earn a commission on any affiliated purchases.

Stacks FX Thsee Anomaly Review

Stacks FX Thsee Anomaly Review

This Long Beach builder's latest features cool real-time control options and demented delay for days.



Demented delay for days. Tap-tempo modulation. Real-time control. Excellent build quality.

No tap-tempo delay. Pricy.


Stacks FX Thsee Anomaly


Ease of Use:



The Thsee Anomaly is a large-format delay pedal from Stacks FX, a boutique builder from Long Beach, California. Unlike all those modern digital delays that go to great lengths to mimic analog sounds, Thsee Anomaly marches in the opposite direction. It revels in its digital-ness, with an emphasis on glitches, noise, and other, um … anomalies.

Cheap Chic
The pedal’s core processor is the PT2399, an inexpensive delay chip that’s been used in countless DIY projects. The chip has a reasonably clean sound for short delays, but its tones degrade dramatically at longer settings. The Thsee Anomaly has a high maximum delay time (1.5 seconds), so there are plenty of opportunities for delay degradation. In addition to smeary, lo-res tones, long delays introduce scritchy-scratchy digital noise that Stacks FX coyly refers to as “space dust.”

The delay controls are relatively straightforward: delay time, feedback, and mix, plus a low-pass tone control to darken the wet signal (and de-emphasize that space dust). A dedicated jack lets you control delay times via expression pedal (not included). Another cool feature is “swell,” a secondary feedback control with its own knob and momentary footswitch. When you press, the wet signal leaps to a high regeneration setting. (How high depends on the swell knob setting.) It’s perfect for summoning vicious noise squalls that evaporate as soon as you lift your foot.

Weebles Wobble
Delay is only one half of the Thsee Anomaly’s evil recipe. There’s also an ambitious optical modulation section. In addition to the expected rate and depth controls, there’s an 8-position waveform selector offering everything from smooth sine waves to chaotic sample-and-hold sequences. A tap-tempo switch sets the LFO speed. However, it does not control the delay time. For that, you must connect a controller pedal or manipulate the delay time knob.

Thsee Anomaly’s wide LFO rate range and multiple waveforms conjure endless mutant modulation sounds.

The modulation section also includes a multiplier control, which can interpret quarter-note foot taps as anything from half-notes to 16th notes. That’s handy, because at ultra-fast speeds (faster than your foot can tap) the LFO enters the audio spectrum, generating some ring-mod effects—notably a ferocious sub-octave.

On most delay pedals, adding an LFO unlocks phaser/flanger/vibrato sounds. That’s true here, but to a greater extreme. The Thsee Anomaly’s wide LFO rate range and multiple waveforms conjure endless mutant modulation sounds, especially when combined with the weird things that happen to the wet signal at long delay settings.

The Thsee Anomaly is beautifully made. The components reside on two hand-populated circuit boards. All jacks and pots are enclosure-mounted. Four internal trim pots fine tune the pedal’s response. The soldering and wire routing are stellar. All 10 knobs are metal—a classy touch. The pedal runs on any conventional 9V power supply (not included). There is no battery option.

The Verdict
If you’re still reading, perhaps you’re the sort of tone pervert who can make good use of these lowest-of-fi sounds. Interpret my tones rating accordingly. If you dig such stuff, the pedal rates four or higher. If you only want conventionally clean echoes, knock off two or three points. The pedal can sound warmly musical at modest settings and weirdly musical at extreme ones. The $399 price is lofty. But that buys you a handbuilt, large-format, U.S.-made pedal full of unique sounds that must have required substantial R&D. You don’t have to be a freakazoid to like the Thsee Anomaly, but it helps.