The Keeley Seafoam Chorus is a digital chorus pedal from Keeley Electronics, announced in late 2013 with the first 200 units shipping that December1. It sits in the chorus family, but its defining trick is the Blend knob: turned one way it is a chorus, turned the other it becomes pitch vibrato, with every point in between available1. Keeley pitched it as a small-footprint pedal with a wide range of versatility, and Robert Keeley himself described it to Premier Guitar as his most exciting design since his popular compressors12.
What the Seafoam does
Chorus works by mixing a slightly delayed, modulated copy of your signal with the dry signal. The Seafoam's Blend control decides how much of that wet copy you hear, and at the far end of its travel it removes the dry signal entirely, which turns the effect from chorus into pitch vibrato1. Pedal of the Day called this the Vibrato Blend Control, a way to "ride the line between vibe and chorus"5.
Vintage Guitar's reviewer found the pedal covers a wide span of that territory, describing it as "a very versatile effect that can do a lot of things well, from a subtle chorus to shimmering to a heavy warble vibrato"3. With the knobs around 12 o'clock, Pedal of the Day reported "you get this sweet shimmering boost that just adds a brightness to whatever you play"5. Premier Guitar's reviewer summed up its range as "Great chorus and vibe tones, ranging from glossy to warm or weird"2.
The circuit is unusual. According to Keeley, it combines an IC chip rarely used for chorus applications, the Ericson ES56033, with an opto-isolator LFO2. The maker says the opto-coupler is there specifically to give the depth control a smooth sound1. Although the pedal is digital, Vintage Guitar found its low-noise circuitry to be a breakthrough, noting the kind of quietness that is almost always found in analog chorus units3. In use that meant "next to zero background noise," a welcome change even with a high-gain amp3.
Delicious Audio reported that the pedal was designed with professionals and studios in mind, featuring a custom noise canceling circuit using Burr Brown SoundPlus technology, an active tone control, and the company's signature JFET amplifiers6. It is housed in a powder-coated enclosure painted seafoam green, hand-built in the U.S.43.
The controls
Four knobs run the show, and Premier Guitar's reviewer considered the two less common ones the real keys to the pedal's potential2.
| Control | What it does |
|---|---|
| Rate | Sets the speed of the modulation3 |
| Depth | Sets how deep the effect goes, smoothed by the opto-coupler circuit1 |
| Tone | Varies the overall sound from mellow to a bright shimmer3 |
| Blend | Moves from chorus to pitch vibrato1 |
Keeley describes the Tone control as letting you go from shimmery to smooth warmth1, and Pedal of the Day framed it as a way to perfect any vintage analog sound or modern shimmer, noting the pedal is designed for both guitar level and effects loop levels5. The maker's own summary is straightforward: with Rate, Depth, Tone and Blend, "it's simple to find your creative muse with this tone tool"1.
What reviewers said
Published reviews were positive across the board:
- Premier Guitar highlighted the pedal's "Exceptional tonal control," crediting the tone knob, and praised the range of chorus and vibe tones from glossy to warm or weird2.
- Vintage Guitar found it very versatile, from subtle chorus to shimmering to heavy warble vibrato, with next to zero background noise even into a high-gain amp3. The reviewer also found it gave a Les Paul chime through a Marshall when the guitar's volume was rolled off slightly, calling it "very useful for a Gibson player who wants to produce clean and vibey tones without having to switch guitars"3.
- Pedal of the Day called it "a great looking, solid, well built feeling pedal" and highlighted the shimmering boost available with the knobs around noon5.
The Seafoam Plus and the Stereo Seafoam
The original Seafoam was followed by two related pedals. At NAMM in January 2014, Keeley announced a Stereo Seafoam Chorus alongside the Clipper Fuzz and Compressor Pro7.
In November 2015 came the Seafoam Plus Chorus, a tri-mode chorus with internal switching between modes8. It ships in Modern Mode for what Guitar Interactive described as ultra wide, lush and high fidelity chorus, with an internal switch selecting Vintage Mode for a softer, silky smooth and warm sound8. Its Seafoam Mode reproduces the same really long delay the original Keeley Seafoam is famous for, with the Mix control rolled all the way up for vibrato8. A Dual Chorus Mode uses a cross-over based dual chorus engine with independent depth control for highs and lows8, and a Space control adds regeneration, high pass filtering and a tremolo in the flanger mode8. Keeley even voiced the chorus tone to sound like a 1959 Marshall Super8. Like the original, the Seafoam Plus is designed and hand built in Edmond, Oklahoma9.
The original Seafoam Chorus dates from 2013 and 2014. Players comparing it against later Keeley modulation pedals should check which version a listing refers to, since the Seafoam Plus is a different, multi-mode pedal rather than a revision of the original four-knob design13.
For players exploring Keeley's broader modulation line, the company also makes pedals such as the Keeley Dyno My Roto tri-chorus and rotary pedal.
Videos
Premier Guitar
Premier Guitar
Prymaxe
Questions
Is the Keeley Seafoam Chorus analog or digital?
It is digital. Keeley described it as a digital chorus designed from the ground up with the company's voicing and attention to detail, and Vintage Guitar's reviewer noted its low-noise circuitry, a trait usually associated with analog chorus units instead.
Is the Keeley Seafoam Chorus true bypass?
Yes. Vintage Guitar reported the pedal is wired with true-bypass switching, and its full review confirmed the true-bypass design in a small-footprint, seafoam green powder-coated enclosure.
What chip is in the Keeley Seafoam Chorus?
The Ericson ES56033, an IC chip rarely used for chorus applications, paired with an opto-isolator LFO. Keeley says the opto-coupler is what gives the depth control its smooth sound.
Is there a stereo Keeley Seafoam Chorus?
Yes. Keeley announced a Stereo Seafoam Chorus among the pedals slated for release at its NAMM show in California in January 2014, alongside the Clipper Fuzz and Compressor Pro.
Where is the Keeley Seafoam Chorus made?
In the United States. Vintage Guitar reported it is hand-built in the U.S. with high-quality components, and Pedal of the Day listed it as 100 percent made in Edmond, Oklahoma, where Keeley is based.
What is the difference between the Seafoam Plus and the original Keeley Seafoam?
The Seafoam Plus is a tri-mode chorus with internal switching between Modern and Vintage modes, plus a Seafoam Mode that reproduces the long delay the original is famous for, and a Dual Chorus Mode with independent depth control for highs and lows. The original is a simpler four-knob chorus that blends into pitch vibrato.
Sources (9)
- NEW Keeley Seafoam Chorus Starts Shipping!, Keeley Electronics Guitar Effects Pedals, 2013-10-03
- Keeley Seafoam Chorus Review, Premier Guitar, 2014-06-12
- Keeley Electronics Seafoam Chorus, Vintage Guitar magazine, 2015-03-13
- Keeley Adds Seafoam Chorus Pedal, Vintage Guitar magazine, 2014-03-05
- Keeley Electronics Seafoam Chorus, Pedal of the Day, 2014-06-04
- New Pedals: Keeley Electronics Seafoam Chorus, Delicious Audio, 2013-10-17
- Keeley Reveals 4 More New Effect Pedals, Keeley Electronics Guitar Effects Pedals (robertkeeley.com), 2014-01-15
- Keeley Electronics Unveils the Seafoam+ Vibrato Chorus, Guitar Interactive Magazine, 2015-11-11
- Keeley Electronics Unveils the Seafoam+ Vibrato Chorus, Premier Guitar, 2015-11-10
