The Walrus Audio Slö Multi Texture Reverb is a compact reverb pedal built for ambient playing. Released in 2019 and made in the USA, it lets players, in Walrus Audio's words, "create lush, modulated, sleepy and ambient soundscapes" through three algorithms selected by a toggle switch: Dark, Rise and Dream12. Designer Jason Stulce drew on lessons learned creating the Fathom reverb when developing it3.
What it does: three ambient reverb textures
A toggle switch selects between three reverb modes, and each mode gives the X knob a different job1.
| Mode | What it does | What the X knob does |
|---|---|---|
| Dark (Lower Octave) | Adds a lower octave to the reverb trail for deep, wide atmospheric sounds and what Walrus calls nightmarish soundscapes15 | Sets the level of a -1 octave signal feeding the reverb1 |
| Rise (Ambient Swell) | Auto-swell reverb for cinematic swells15 | Sets how long the reverb takes to swell in after a note; lower for shorter rise times, higher for longer1 |
| Dream (Latching Pad) | Lush reverb with a latching pad function; the pad decrescendos according to the decay knob setting14 | Sets the depth of vibrato applied to the reverb trail1 |
On top of the three algorithms, the Slö offers three wave shapes for the modulation on the reverb trail, accessed by holding down the bypass switch while switching the algorithm toggle15:
- Sine: smooth and even pitch up and down modulation5
- Warp: asymmetric pitch up modulation, similar to a warped record5
- Sink: asymmetric pitch down modulation for a sinking detune, which Walrus compares to a Bigsby1
The pedal runs on the FV-1 DSP chip. Stulce told Guitar.com that a central design challenge was "figuring out how to have complex LFO wave shapes modulate the reverb with the limitations of the FV-1 DSP chip"3.
Footswitches: momentary bypass and sustain
The two footswitches are where the Slö's performance tricks live4.
- Bypass: when the pedal is off, press and hold to temporarily activate the effect for a moment of reverb texture; releasing it turns the effect off and fades it out15.
- Sustain: when pressed, it ramps the reverb trail up to maximum for a long, dreamy trail, then ramps back down to the decay knob setting when released. In the Dream algorithm it is latching: press once to capture and sustain the current reverb decay, press again to let the trail taper off based on the decay knob position14.
Stulce described one way he uses it: "You can use the sustain switch to drag out notes and landings of phrases"3. He pairs the pedal with quiet, clean picked parts, along with the ARP-87 delay and the 385 overdrive3.
The Slö can run in trails or no trails mode, toggled by holding down the bypass switch for one second while applying power1.
The Slö uses buffered bypass, not true bypass1. If you want the reverb tail to continue after switching off, set it to trails mode at power-up.
Where it came from
Walrus Audio released the Slö in 2019, and Guitar.com called it "one of 2019's must-try effects"3. Its circuit lineage runs through the Fathom reverb, whose development taught Stulce lessons he carried into the Slö's design3. The pedal is made in the USA2 and carries Walrus Audio's limited lifetime warranty5.
At launch, MusicRadar listed it at $199/£192/€2096, and Gearnews gave the RRP as USD 199 / GBP 1927. Walrus Audio's current listing prices it at $219.99, with blemished units (cosmetic scratches or dents only) at $186.991.
What reviewers said
The Slö collected strong press in its release year and after:
- JHS named it their reverb of the year for 20198
- It made the Best of 2019 lists for EytschPi42 and Guitar.com8
- It was the top choice for shoegazer videographers Pedal Partners8
- It ranked number 1 with 13 points in Delicious Audio's Best Pedals of 2019 aggregate chart8
- Delicious Audio added it to its list of the 24 Best Ambient/Shoegazer Reverb Pedals4
Guitar.com's review, by Michael Watts, described it as a "multi-voiced reverb pedal with deep functionality"2. In the site's Best Effects Pedals of 2019 awards, its verdict was:
"Fans of self-oscillating, end-of-the-gig pedalboard wig-outs will find a new friend here."
Slö vs Slötvå
The Slötvå Multi Texture Reverb is a variant of the Slö that adds the ability to create and save three presets10. MusicRadar put it simply: "The Slötvå simply takes the existing Slö pedal and adds three preset slots"11. The core sound, the lush, modulated, sleepy and ambient soundscapes, carries over10. If you switch between settings live, the Slötvå saves you bending down; if you set one sound and leave it, the Slö does the same job for less.
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Questions
Is the Walrus Slö true bypass?
No. The Slö uses buffered bypass, according to Walrus Audio's product page. It can also run in trails or no trails mode, toggled by holding down the bypass switch for one second while applying power, so you can choose whether the reverb tail continues after you switch the effect off.
Does the Slö have trails mode?
Yes. Walrus Audio says the Slö can run in trails or no trails mode. You toggle between them by holding down the bypass switch for one second while applying power. Trails mode lets the reverb tail fade out naturally after bypassing instead of cutting off.
What is the difference between the Slö and the Slötvå?
The Slötvå Multi Texture Reverb is a variant of the Slö that adds the ability to create and save three presets. MusicRadar describes it as taking the existing Slö pedal and adding three preset slots. The core algorithms and ambient character are otherwise the same.
What chip does the Walrus Slö use?
The Slö is built on the FV-1 DSP chip. Designer Jason Stulce told Guitar.com that a key challenge of the design was figuring out how to have complex LFO wave shapes modulate the reverb within the limitations of that chip.
What power supply does the Slö need?
The Slö requires 9V DC with a minimum of 100mA. Walrus Audio recommends an isolated power supply for all its pedals and does not recommend daisy chain supplies. The power supply is not included with the pedal.
Sources (11)
- Slö Multi Texture Reverb, Walrus Audio
- Review: Walrus Audio Slö Multi Texture Reverb, guitar.com, 2019-04-15
- The inside story of Walrus Audio’s Slö Multi Texture Reverb, one of 2019’s must-try effects, guitar.com, 2019-04-17
- Walrus Audio Slö Multi Texture Reverb, Delicious Audio, 2023-04-19
- Slö Multi Texture Reverb, Walrus Audio
- Walrus Audio unveils ethereal Slö Multi Texture Reverb, MusicRadar, 2019-04-15
- Walrus Audio Slö Multi Texture Reverb puts inspiring, ethereal sounds on tap, gearnews.com, 2019-04-17
- Best Guitar Pedals Of 2019, Delicious Audio, 2020-02-07
- Gear Of The Year: Best effects pedals of 2019, Guitar.com, 2019-12-03
- Slötvå Multi Texture Reverb, Walrus Audio
- Our 11 favourite effects pedals of 2022, MusicRadar, 2022-12-22
