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Keeley Seafoam Chorus Review

Lush modulation and faux-Leslie tones that may just convert even longtime chorus haters.

If there’s one effect that tends to get a bum rap, it’s chorus. Sure, opinions vary, but if you polled players about the least-necessary stompbox, the swishy modulator would be at or near the top of the list. Rationales would cite cheesy pop songs where the guitar is so chorused that it sounds artificial and overproduced. For a long time I felt the same way.

But haters forget what a profound impact judiciously applied chorus has had on timeless tunes in almost every genre. Andy Summers is one of the most respected chorus addicts—pretty much every note he played on Police hits has it. Subtle chorus transformed Danzig’s brooding metal anthem “Mother” from a plodding power-chord exercise to a simmering fist-pumper. Chorusing is similarly indispensible to classic rockers by the Cult and Metallica. Nile Rodgers funk fests that have set booties shaking around the globe wouldn’t be the same without it. Even Kurt Cobain—Mr. Raw—used chorus.

Yet the stigma remains. So you’ve got to admire Oklahoma stompbox builder Robert Keeley for diving in with such enthusiasm on his latest pedal, the Seafoam Chorus. He giddily describes the Seafoam as his most exciting design since his popular compressors. According to Keeley, the Seafoam’s circuit is based on the notion of combining an IC chip rarely used for such applications—the ES56033—with an opto-isolator LFO. Whatever the methodology, the results are remarkable.

Without adequate tweakability, certain guitars need a level or treble boost to make the chorused signal cut through as well as non-chorused sounds. With the Seafoam, this concern is obliterated.

Foaming at the Mouth
Besides the expected rate and depth knobs, the Seafoam includes tone and blend controls, and they’re the real keys to this green machine’s potential. Turned counterclockwise, blend serves up the Doppler dandiness of vintage-style vibrato circuits. At the other extreme it conjures the Seafoam’s watery namesake effect. In between are intriguing blends. (Considering today’s chorus ambivalence, it stumps me why the Seafoam’s enclosure doesn’t proudly shout “Vibrato.” Plenty of players who won’t go near chorus have a soft spot for other pitch-warbling effects.)

Beach Bums and Rayguns
I tested the Seafoam using a Tele with Curtis Novak pickups, a Danelectro ’56 Reissue Baritone, a Schecter Ultra III with a TV Jones Magna’Tron, and a Gretsch solidbody with a P-90 bridge pickup. My test amps were an EL34-powered Jaguar HC50 combo and a 6973-powered Goodsell Valpreaux 21.

Given my predilection for taut tones with plenty of bite, I immediately took to the Seafoam’s tone knob. Many chorus pedals—especially vintage-style ones—either have no EQ control or a one-size-fits-all bright toggle. Without adequate tweakability, certain guitars need a level or treble boost to make the chorused signal cut through as well as non-chorused sounds. With the Seafoam, this concern is obliterated.

Thanks to the tone knob’s wide range, you can plug in a darker-sounding humbucker axe, set blend to the vibe side, adjust tone to taste, and put rate and depth past noon for a trippy “Black Hole Sun”-style solo. You can then switch to a bright single-coil guitar, tweak the tone again, dial back depth and rate, and add some slow echo for a hypnotic space-rock effect. In other words, the tone knob avoids having to compromise the strengths of either instrument. I can’t overstate how effective this control is, especially since the Seafoam’s sound becomes brighter as you shift from vibrato to chorus.


Great chorus and vibe tones, ranging from glossy to warm or weird. Exceptional tonal control.

Could use an expression-pedal input or strategically located knob for real-time rate control.


Ease of Use:




Keeley Seafoam Chorus

Is Maggie There?
When vibrato aficionados get together, the acid test is often, “Yes—but can it do Magnatone vibrato? I thought not. Tsk-tsk.” Keeley doesn’t tout this as a Maggie in a box, and it’s not. But if you’re looking for a neck-snapping, motion-sickness-inducing vibe, you’ll find plenty of weirdness here. One of my favorite recipes was conjuring wicked ray-gun sounds by plugging my Dano Bari or my D-tuned Schecter into an EarthQuaker Devices Tone Reaper fuzz, and then into the Seafoam with rate and depth to 2 or 3 o’clock. Bring on the alien invasion!

The Seafoam sounds very good on the chorus side, too. With a clean tone and my Tele’s bridge pickup and Jazzmaster neck pickup engaged, I set rate and depth around noon for barely audible motion, perfect for Nile-style funk, and then nudged both higher for undulating ’80s new wave tones in the style of the Fixx. It’ll also do full-on slosh for your ’80s hard rock, or animate grunge tones with aplomb.

The Verdict
Whether you’re looking for over-the-top or subtle chorus/vibrato, the Seafoam flat-out delivers. Its tone-connoisseur sonics are remarkably moldable, thanks to the powerful tone knob. With some players or rigs, the blend control’s gradual vibrato/chorus taper might feel a bit too subtle. I usually set it to full vibrato, full chorus, or a 50/50 blend, but some players might find other blends invaluable. Headier effect users may lament the lack of an expression control input to alter the LFO rate in real time. (Even vintage-chorus fans might wish the rate knob were sized and positioned for easier foot-nudging.) Tweakers might also wish they could alternate between two or more favorite settings. But those things would cost more money and board space, not to mention sacrifice the simplicity most guitarists prize. When all’s said and done, players who prioritize stellar tones, straightforward operation, and economy of scale will be stoked by the quality and power of this compact, easy-to-use box.

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