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

Keeley Octa Psi Review

Keeley Octa Psi Review

Fuzz, octave, and odd intervals co-mingle and clash with bizarre, mangled, musical, pretty, and often shockingly unpredictable results.

Scores of tones that span the musical and the ridiculous. Fun and ferocious fuzz. Octave can be used independently. Often intuitive in spite of its complexity. Tracks pitch shifts without glitches

Easy to get lost in the weeds if you don’t do your homework.

$249

Keeley Octa Psi
robertkeeley.com

4.5
4.5
3.5
4.5

I’d venture that most guitarists instinctively regard fuzz as a brutish, brainless effect (which is funny given how much energy in our community is dedicated to dissecting the nuances and merits of different fuzz types). Keeley’s Octa Psi, however, transcends mere troglodyte status by combining a fundamentally nasty fuzz voice in three switchable variations, and a web of octave and interval tones that transform the Octa Psi into a synthesizer capable of textures ranging from soaring to demented to downright evil.


Crush of the Space Invader

It’s no mistake that the little figure adorning the face of the Octa Psi looks like a sinister cross between a Space Invader and a Cylon. The Octa Psi often evokes the 8-bit, synthy sounds of ’80s arcade games. But the fact that the Octa Psi’s sounds range to cartoonish extremes shouldn’t suggest to a potential user that the Octa Psi is anything less than musical. And the smart, if complex, control layout ensures you can span both extremes with ease.

The Octa Psi is effectively made up of an analog fuzz and a digital octave section. The knobs on the fuzz side are no-brainer stuff: fuzz, master level, and tone. The 3-position toggle, however, expands the potential of those three knobs exponentially. In each mode the fuzz has a cool, snorkel-y, almost filtered essence, with hints of cocked-wah snarl. The punch voice features a bass-heavy profile that’s cloaked in pea-soup fog at the extreme treble-cut/bass-boost ends of the tone control’s range, but crushes like a Tony Iommi-operated wrecking ball in the middle section. The psi mode is even thicker and doomier, though not just heavier in the bass. There’s also more midrange presence that lends extra definition and makes the fuzz feel more explosive under the fingers. The scoop setting, in very relative terms, sounds almost thin compared to the other two. But no voice is exactly short on power here, so perhaps it’s best to call it focused. Each of these modes, which already have heaps of tonal range thanks to the versatile tone knob, can be altered dramatically by the octave section.

Getting a feel for the octave options definitely takes practice. And though intuitive exploration of the possible combinations is rewarding, it’s essential that you do your homework if you want to maximize the pedal’s potential and avoid musical muddles. The Octa Psi’s complexity is largely down to the fact that it gives you much more than just a few octaves up or a few octaves down to work with. First, you can blend in the amount of octave signal. Then there are eight pitch modes available via the rotary switch. Each of these modes shifts in character, depending on whether you select the octave up, octave down, or dual octave setting with the toggle switch. But you can also reshape the tone by pressing and rotating the blend switch, which, depending on where you’ve set the other octave controls, will add octave intervals, like sharp ninths, stacked fourths, and major and minor voicings. Additionally, each of the preset modes will save your settings in dual mode—even after you unplug.

 Controlled Chaos

There is another reason the video game correlation implicit in the Octa Psi logo is appropriate: At times, using it can feel like the sky above your moon base is raining laser bombs and you’re being menaced by alien aircraft from all sides. It can be really chaotic, particularly if you’re finding your way by ear rather than consulting the extensive pitch matrix in the manual. Chords are sometimes rendered into atonal glop, and, like any octave fuzz, it’s often easiest to stick with single-note lines.

But for all the mayhem Octa Psi can unleash, finding a clear musical path can be easy and feel like striking gold. Plus, the pedal is, in its way, quite forgiving. It tracks pitch changes well, and rarely collapses on itself—even when executing whole step bends colored by dissonant intervals. You can also use the octave without the fuzz, which yields conventional sounds like pretty faux-12-string, watery chorus tones, and subtle harmonies for clean leads.

The Verdict

The Octa Psi’s power and tonal vocabulary is impressive. You’ll have to be brave or have a very good memory to move between radically different settings on a dimly lit stage. And we didn’t even mention the wealth of “advanced” settings that include volume tilt, pitch ramping, effect order shifts, and more. But the bounty of smooth-to-sick sounds here means the Octa Psi could be a difference-maker in a studio or recording environment when you’re reaching for tone colors and moods that break norms. And though the Octa-Psi could, on the surface, seem nichey, it’s fun to think about the many musical styles and applications where its sounds could find a home—from doomy Sabbathoid chug, to film scores, to glitchy hip-hop hooks, to video-game sound design.

Featuring updated circuits for maximum fidelity, intuitive controls, and true stereo capabilities, this pedal offers a rich chorus effect with tube-like overdrive.

Read MoreShow less

Pearl Jam announces U.S. tour dates for April and May 2025 in support of their album Dark Matter.

Read MoreShow less

The legendary German hard-rock guitarist deconstructs his expressive playing approach and recounts critical moments from his historic career.

Read MoreShow less

Katana-Mini X is designed to deliver acclaimed Katana tones in a fun and inspiring amp for daily practice and jamming.

Read MoreShow less