The Electro-Harmonix Oceans 12 is a dual stereo reverb pedal released in 2020. Where most reverb pedals give you one engine, the Oceans 12 carries two simultaneous, independent, stereo reverb engines, so you can run two different reverb sounds at the same time, in mono, dual-mono, parallel or even in series12. Electro-Harmonix describes it as "the Oceans 11's big brother with even more reverbs and functionality"1.
It is a digital pedal with 12 reverb types, 24 presets, tap tempo and an infinite sustain-style attenuation control, all in a box Premier Guitar called compact for a pedal with this many options13. In May 2025, Guitar Pedal X reported that the Oceans Abyss takes over from the Oceans 12 as EHX's flagship reverb workstation, so the Oceans 12 now sits one rung below the top of the line4.
Two stereo reverb engines in one pedal
The core idea of the Oceans 12 is the second engine. The Oceans 11, released in 2018, packed 11 reverb types into a single pedal; the Oceans 12 takes that one step further, hence the name, by adding an extra reverb engine7. Each engine is stereo and independent, with its own footswitch carrying Bypass, Tap and Infinite controls1.
Gearnews described the payoff at launch: "It can fire two reverbs simultaneously, in mono, dual-mono, in parallel or even in series"2. In practice that means you can put a spring reverb on one engine and a shimmer on the other, blend them, or route one into the other. Premier Guitar's reviewer found that "combined reverb sounds create ultra-rich textures"3.
Within the EHX reverb family, Premier Guitar placed the Oceans 12 between the bigger Cathedral and the more compact Oceans 11, both of which cover some of the same ground, but judged that the Oceans 12 strikes a practical balance between the two3.
The twelve reverb types
The pedal offers 12 reverb types: Room, Spring, Plate, Reverse, Echo, Trem, Mod, Dyna, Auto-Inf, Shimmer, Polyphonic and Resonant6. Several types contain multiple modes, which the MODE button cycles through, for a total of 29 algorithms18.
| Reverb type | Modes | What each mode is |
|---|---|---|
| ROOM | 2 | Reverb algorithms modeled after a lively room and a spacious performance hall1 |
| SPRING | 2 | Vintage 1962 Fender 6G15 tube reverb emulation, and the spring algorithm from the EHX Holy Grail1 |
| TREM | 3 | A classic, periodic volume envelope with various shapes applied to both the wet and dry mix of a hall reverb1 |
| MOD | 3 | Combinations of chorus and flange reverbs that create rich reverb tails1 |
| RESONANT | 2 | Reverb excited by tunable resonators and configurable self-oscillating filters on the reverb tail1 |
Guitar World's Trevor Curwen found the 12 single reverbs "offer everything from a twangy emulation of a vintage Fender 6G15 outboard spring unit, through reverb combined with echo or modulation, to infinite shimmery ambiences"6. Premier Guitar's reviewer described the room mode as relatively soft and subtle, with options for hall mode, subdued modulation, and a pre-delay feedback control; the tremolo reverb mode ranges from soft, throbbing, almost subliminal modulations to chirping ring-modulated sounds; and the reverse reverb can feel seamless and organic or mechanical and alien depending on time, tone, or pre-delay settings3.
The controls
The front panel is built around the two engines and their shared controls:
- REVERB A footswitch: controls Reverb A with Bypass, Tap and Infinite controls1
- REVERB B footswitch: controls Reverb B with Bypass, Tap and Infinite controls1
- SELECT button: toggles between reverb engines1
- MODE button: cycles through the available modes of the selected reverb type1
- PREDELAY knob: sets the pre-delay time for the reverb block for all reverb types except Echo, Shimmer and Resonant1
- Tide Control: a new control for stereo image alteration1
- Infinite attenuation control and a Lo-fi Control1
- Tap tempo: sets pre-delay time, echo time and more1
- 24 presets store your settings1
There is also an input jack for external expression and 3-button footswitch control1. Premier Guitar noted one wrinkle in the switching scheme: switching between the two reverb engines requires you to select a default reverb first, which also reverses the location of the bypass switch depending on which engine is the default3.
Power and connections
The pedal runs on the standard EHX 9.6DC200mA power supply, which is included, and draws 150mA19. Connections are standard for a stereo pedal with a loop:
| Jack | Function |
|---|---|
| L/MONO input | Either the mono audio input or the left stereo input1 |
| R/RETURN input | The right input in a stereo setup; can also be the RETURN signal in SEND/RETURN mode1 |
| L/MONO output | Output for a mono setup; the left output in a stereo setup1 |
| R/SEND output | Also serves as an FX loop output1 |
| COMBO EXP/FSW jack | Accepts either an expression pedal or an external footswitch1 |
Guitar World lists the connections as standard inputs (L/Mono, R/Return), standard outputs (L/Mono, R/Send) and EXP/FSW6.
The 150mA current draw is on the high side for a compact pedal. If you power a board from a daisy chain, budget a dedicated output for the Oceans 12 rather than sharing with other digital pedals.
What reviewers said
Reviews were positive, with some caveats about the learning curve. Premier Guitar's verdict: "The Oceans 12 is a cool option for a player that wants a deep, powerful, and adaptive reverb for a compact pedalboard"3. The same review flagged that "activating some functions can be confusing," noted the absence of preset scrolling, and advised that "delving into those 37 pages will save time you'll otherwise spend hunting for hidden functions," referring to the manual3.
Guitar World's Trevor Curwen concluded: "With two independent or combinable reverbs in a pedal that won't take up much space at all on your 'board, this is a potent ambience tool at a decent price overall"6. Delicious Audio's readers' poll of the best guitar pedals of 2020 placed the Oceans 12 in 11th place with 2 points101.
Videos
Premier Guitar
EHX
Guitar Bonedo
News
Questions
Can the Oceans 12 run both reverbs at once?
Yes. The pedal has two simultaneous, independent, stereo reverb engines, each with its own footswitch for bypass, tap and infinite control. The two reverbs can fire simultaneously in mono, dual-mono, parallel or even in series, which lets you stack two different reverb types into one sound.
Is the Oceans 12 true bypass?
No. Electro-Harmonix specifies a buffered bypass for the Oceans 12. A buffer keeps the signal consistent through long pedalboard chains, though players who prefer a true-bypass switching style will want to note this before buying.
Does the Oceans 12 have tap tempo?
Yes. Tap tempo sets the pre-delay time, echo time and more. Each of the two reverb engines has its own footswitch carrying Bypass, Tap and Infinite controls, so both engines can be tapped independently.
Has the Oceans 12 been discontinued?
In May 2025, Guitar Pedal X reported that the Oceans Abyss takes over from the Oceans 12 as Electro-Harmonix's flagship reverb workstation. The Oceans 12 has therefore been superseded at the top of the EHX reverb line, though it remains a widely available pedal on the used and new market.
What power supply does the Oceans 12 need?
It runs on the standard EHX 9.6DC200mA power supply, which is included in the box, and draws 150mA. That current draw is high enough that sharing a small daisy-chain supply with other pedals can be a problem, so a dedicated output is the safer approach.
Sources (10)
- Oceans 12, Electro-Harmonix
- Electro-Harmonix Oceans 12: new demo video goes online, gearnews.com, 2020-02-28
- Electro-Harmonix Oceans 12 Review, Premier Guitar, 2020-10-15
- Guitar Pedal X, Guitar Pedal X, 2025-05-19
- Waves collide in Electro-Harmonix’s Oceans 12 dual stereo reverb pedal, guitar.com, 2020-02-27
- Electro-Harmonix Oceans 12 review, Guitar World, 2021-06-14
- Electro-Harmonix Oceans 12 Dual Stereo Reverb, Delicious Audio, 2020-10-20
- Guitar Pedal X, Guitar Pedal X, 2021-08-16
- Is the new Electro-Harmonix Oceans 12 the only reverb pedal you'll ever need?, MusicRadar, 2020-02-27
- The Best Guitar Pedals Of 2020 according To The Internet Experts, Delicious Audio, 2021-01-21
