The Walrus Audio Slöer is the third evolution of the Slö pedal, a compact, mono reverb designed to deliver a textural, rather than realistic, effect ideal for music with ambient and droney inclinations. It was such a resounding success, that the Oklahoma-based company soon followed it up with a version with presets, the Slötva. The Slöer goes even further: it’s the stereo version of the Slötva, and adds two new algorithms.

True, the footprint of this third Slö-volution is almost twice as big as the original, and while that’s understandable considering the doubling of the channels, it’s also worth noting that it allows for more space for improved controls, like the two faders placed in the heart of the pedal: one sets the inherited, mode-dependent X parameter, while the other controls the new Stretch function, which changes the reverb’s sample rate for less pristine if not downright lo-fi effects.

There’s a new rotary Mode knob that replaces the 3-way toggle switch from the mono versions of the pedal, adding the new Rain (Delay Tap Diffusion) and Light (High Octave Shimmer) modes on top of the three ones inherited from previous versions (but now in stereo): Dark (Lower Octave), Rise (Ambient Swell), and Dream (Latching Pad). You can read in-depth descriptions of all the modes here.

Another new feature intrinsically linked to the stereoness of the pedal is the 3-way Width toggle, which delivers three stereo modes with an increased, normal, or reduced stereo effect – the wider, the more open-sounding.

Just like in the previous versions, all these modes have optional modulation whose depth can be manipulated with the Depth knob and whose Rate can be changed by holding down the bypass switch and turing the depth knob. Rotating the Mode knob while pressing the Bypass footswitch also allows to pick between 5 Modulation Waveforms.

Both the Trail modes and the momentary footswitch functions found in the mono devices are carried on here (momentary texture for the bypass switch and maximum momentary trail for the Sustain footswitch).

Without further ado, here are the sonically enveloping sounds produced by the Walrus Audio Slöer.

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Walrus Audio Slöer, Builder’s Notes

The Slöer Stereo Ambient Reverb builds on our popular Slö lineup but adds two additional reverb algorithms, stereo width control, two additional modulation wave shapes, and the ability to control the sample rate. Now you can create immersive, lush, modulated, sleepy, and ambient soundscapes with more width and depth than ever before.

Save your favorite dreamscapes with three onboard presets by simultaneously pressing and holding down on the bypass and sustain switches. Scroll through them by simultaneously pressing and releasing bypass and sustain.

The five-way rotary dial allows five different reverb modes – the three you know and love from the Slö: Dark (Lower Octave), Rise (Ambient Swell), and Dream (Latching Pad); and the addition of two new modes: Rain (Delay Tap Diffusion) and Light (High Octave Shimmer). Secondary functions on the dial change between five different wave shapes for modulation on the reverb trail.

Combine deep modulation, long washy trails, and an immersive stereo field to experience Slöer.


DARK – Add a lower octave to your reverb trail. Here you’ll create deep and wide atmospheric sounds and channel nightmarish soundscapes. X knob sets the level of a -1 octave signal that feeds the reverb.

RISE – This is an auto-swell reverb for beautiful cinematic swells. Don’t rush it. Let it breathe and gently wake up. X knob sets the amount of time it takes the reverb to swell in after a note is played. Set lower for shorter rise times and higher for longer rise times.

DREAM – Lush reverb with a latching pad function. Press the sustain switch to latch signal. Experiment with the X knob to add vibrato over the pad. Press sustain again and the pad will decrescendo according to where the decay knob is set. X knob sets the depth of vibrato applied to the reverb trail.

RAIN – Tappy and trippy, this program creates a unique effect with lower levels of diffusion allowing the reverb delay taps to audibly create an echo-like effect within your reverb. Use the Xcontrol to set the amount of diffusion of the delay taps.

LIGHT – Bright and smooth reverb with an octave-up shimmer. Create a range of ethereal sounds with the X slider, keep it low for a smooth pad-like reverb or push it higher for a bright shimmer effect.

The Slöer also features five different wave shapes accessible by holding down bypass while switching the algorithm dial.

SINE – Smooth and even pitch up and down modulation.

WARP – Asymmetric pitch up modulation similar to a warped record.

SINK – Asymmetric pitch down modulation for sinking detune similar to a Bigsby.

SQUARE – Symmetric pitch up and down modulation for stepped modulation.

RANDOM – Uses sample and hold that picks new random values.


Bypass: When the switch is in the off position, press and hold to temporarily activate the effect to add a moment of reverb texture. Releasing the switch turns the effect off, and fades it out.

Sustain: When pressed, the decay switch ramps up the reverb trail to maximum creating a long dreamy reverb trail, and then ramps back down to the decay knob setting when released. In the “Dream” algorithm, the sustain switch is latching. Press it once to capture and sustain the current reverb decay for extremely long pad-like sounds. Press it again to let the reverb trail taper off, based on the position of the decay knob.


The Slöer can run in trails or no trails mode. In trails mode, when you turn the pedal off, the reverb decay dies off naturally. In no trails mode, the decay is abruptly cut off when you turn the pedal off. To toggle between either mode, hold down the bypass switch for 1 second while applying power to the pedal. Unplug power and repeat to toggle to the other mode.


When scrolling through presets, there is only preset spillover if the next preset is the same algorithm as the one preceding it. For example, if your red and green presets are both in Dream mode, switching from red to green will not cut your reverb trails.