Electro-Harmonix Oceans Abyss Advanced Reverb Laboratory

The Oceans Abyss Advanced Reverb Laboratory is a digital stereo reverb pedal and multi-effect from Electro-Harmonix, released in 2025. At its heart it is a reverb pedal with dual engines that are independently programmable, and Electro-Harmonix describes it as "a full-featured reverb workstation with in-depth controls over two high-power reverb engines and additional effects blocks for massive end-of-chain tones"¹. It replaced the Oceans 12 as EHX's flagship reverb workstation².

The core idea is that two stereo reverbs are available at once, each fully pannable in the stereo field³. Each of the 128 preset memory slots can load two reverb algorithms simultaneously, and those two reverbs can be assigned to different stereo pan positions⁴. On top of the reverbs, a host of effects including tremolo, chorus, flanger, phaser and a bit crusher are also present, with custom signal paths of up to eight effects blocks¹.

Two stereo reverb engines with added effects

The two reverb engines are the pedal's engine room. Because each engine is independently programmable and each is fully pannable, a preset can place one reverb hard left and another hard right, or blend both toward the center. MusicRadar's review highlighted the ability to "blend two reverbs together in gorgeous stereo"⁷.

The reverb voice set breaks down differently depending on how you count it. Premier Guitar lists 10 reverb types: Room, Hall, Spring, Plate, Reverse, Dynamic, Auto-Infinite, Shimmer, Polyphonic and Resonant⁸. Gearnews counts seventeen, because several of those types come in two variants: Room, Hall, Spring (2x), Plate (2x), Reverse, Dynamic (2x), Auto-Infinite (2x), Shimmer (2x), Polyphonic (2x) and Resonant (2x)⁴.

Two of the voices deserve a closer look:

• Polyphonic offers two configurable bidirectional pitch-shifts within the reverb's tail, which Guitar World called one particular highlight of the voice set¹.
• Auto-Infinite is accessible via long-pressing a footswitch, so an infinite-style reverb can be brought in mid-performance without touching a menu¹.

Around the reverbs sit the additional effects blocks. Tremolo, chorus, flanger, phaser and a bit crusher are all present, and players can build custom signal paths of up to eight effects blocks, which is what turns the pedal from a reverb into a workstation¹.

The controls, modes and footswitches

Each reverb engine gets its own control set. For Reverb A, the panel gives you¹⁴³:

³⁹

There are three footswitches: A, Effect and B. Effect activates the pedal, while A and B activate or deactivate a reverb engine or switch between presets⁴. The footswitches are dual-action, allowing momentary or latching use, so a sound can be held only while your foot is down⁶¹.

Navigation is handled through an OLED screen, illuminated slide pots and buttons, which Guitar World noted are easy to view "on the darkest of stages"¹. The menu offers multiple graphic views, with Signal Path, Performance and Explorer modes depending on how you want to work¹. Almost every parameter is also controllable with an expression pedal, and the EXP jack accepts expression or CV³¹.

Power and connections

The pedal runs on the supplied 9.6VDC / 500mA power adapter, which is included in the box⁶. Premier Guitar confirms the same figure: supplied with a 9.6VDC / 500mA power supply⁸.

The rear panel carries the full connection set: L and R inputs, stereo output, an FX loop with Send and Return jacks, a footswitch input, an expression connection, MIDI In and Out (both 5-pin) and USB-C⁴².

The MIDI implementation is deep. Guitar World reports full MIDI compatibility with nearly every available PC and CC parameter accounted for, alongside a tempo clock for the time-based effects¹. That makes it practical to run from a larger MIDI rig, syncing modulation and pre-delay times to a shared clock.

Where it came from and what it costs

Electro-Harmonix released the Oceans Abyss in 2025², and Guitar Pedal X reported that it replaces the Oceans 12 as the company's flagship reverb workstation². Guitar World framed it as expanding on Electro-Harmonix's award-winning reverb technology¹.

The Oceans Abyss was available now for $495 at launch in May 2025¹, and Guitar Pedal X still listed it at $495 in its 2025 round-up of the best new delay and reverb pedals of the year¹⁰.

Videos

Click to load

Click to load

Click to load