The Lüm Texture Engine is a granular and textural reverb pedal from Walrus Audio. It takes your audio signal and fractures it into tiny "grains" wrapped in different washes of reverb to create sporadic and atmospheric textures1. Walrus describes it as drawing on elements of the Slö Reverb, the Lore Reverse Reverb, and the Fable Granular Generator2, so players who know those pedals will recognize the family resemblance: MusicRadar's Phil Barker wrote that it uses the reverb engine from the Slö Multi-Texture Reverb, the reverse-reverb character of the Lore, and the granular soundscape generation of the Fable3.
The pedal launched in September 2025 as a limited edition of 600 units worldwide4. It returned in July 2026 as a permanent addition to the Walrus lineup in two new colorways, Minimal Black and Guava56.
The three programs and the X knob
The three programs are selected with a 3-way mode toggle3, and each one builds its texture differently.
| Program | What it is | What the X knob does |
|---|---|---|
| I: Grain Cloud | A grain cloud with dual granular taps reading from a feedback delay line4 | Controls grain size, or how frequently you hear the "glitches" happen1 |
| II: Grain Verb | A granular reverb built from dual taps reading from the delay memory of a reverb algorithm tank1 | Controls grain size1 |
| III: Forward / Reverse Verb | A forward reverb algorithm running into a reverse reverb algorithm1 | Controls the reverse reverb decay2 |
The X knob is the pedal's signature control because it changes job with the program: grain size in Modes I and II, reverse reverb decay in Mode III5. Pedal of the Day summed it up as controlling grain size on Programs 1 and 2 and reverse reverb feedback on Program 34.
Alongside X, the control surface carries Mix, Decay and Filter knobs3. The X knob's function changes with the program: it sets grain size, or how frequently the "glitches" happen, on Programs 1 and 2, and the reverse reverb decay on Program 34.
Presets, Moment control and bypass modes
The Lüm saves and recalls up to three onboard presets, denoted by a red, green or blue light23. Sounds fade seamlessly between presets, which Walrus describes as giving smooth live transitions2.
The Moment control is a momentary glide parameter automation control4: hold the switch and the pedal sweeps its parameters for as long as you hold, then releases them when you let go. It is the kind of feature that suits swells and transitions in ambient playing.
For bypass, the pedal offers two modes: Trails, which lets the reverb tail ring out after you switch off, and Instantaneous, which cuts the effect dead4. Players who want clean stops between songs can use the second; players who want the wash to decay naturally can use the first.
The Lüm is a mono pedal, with a mono TS input and a mono TS output5. If your rig is stereo, this is not the pedal for that job. Guitar Pedal X's Stefan Karlsson called it a decent mono textural reverb, perfect for mono rigs, though he wished the ports enabled TRS stereo action5.
Limited run and later reissues
The Lüm's history is unusual. It launched on September 16, 2025 as a limited edition experiment, limited to 600 units worldwide4. It sold out quickly5.
In July 2026, Walrus Audio revived it, reissuing the formerly limited pedal in Minimal Black and Guava Editions5. The reissue returned as a permanent addition to Walrus's lineup due to popular demand, after the original run sold out fast3. So while the original 600-unit run is gone, the pedal itself is no longer limited.
What reviewers said
Published reviewers were positive about the sound. MusicRadar's Phil Barker rated the sounds at five stars out of five3. Pedal of the Day was equally enthusiastic about the overall effect:
"sending your brain on an ethereal, ambient journey the likes of which you might not want to return from…EVER"4
Pedal of the Day, September 16, 20254
Pedal of the Day also offered a practical placement tip: the Lüm is a treat to put before high-gain pedals in mode two4. That is worth trying if you run a distorted amp or drive pedals and want the granular texture to feed into them rather than sit after them.
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Questions
Is the Walrus Audio Lüm analog or digital?
It is a digital reverb. The granular processing that splits your signal into grains, and the reverb algorithms the programs are built from, all run in software, which is what allows the X knob to change function per program and the Stretch knob to time-stretch the effect.
Does the Lüm Texture Engine work in stereo?
No. The pedal has a mono TS input and a mono TS output. Guitar Pedal X's Stefan Karlsson called it a decent mono textural reverb, perfect for mono rigs, though he wished the ports enabled TRS stereo action.
How many presets can the Lüm save?
Three onboard presets, denoted by a red, green or blue light. Sounds fade seamlessly between presets, so switching on stage gives you smooth crossfaded transitions rather than abrupt jumps.
How many Lüm pedals were made in the original run?
The original version was limited to 600 units worldwide when it launched in September 2025, and it sold out quickly. Walrus Audio later brought the pedal back as a permanent addition in two new colorways.
Does the Lüm have trails?
Yes. The pedal offers both a Trails bypass mode, which lets the reverb tail continue after you switch the effect off, and an Instantaneous bypass mode that cuts the sound dead.
Which Walrus pedals is the Lüm based on?
It draws on elements of the Slö Reverb, the Lore Reverse Reverb and the Fable Granular Generator. MusicRadar's reviewer described it as using the reverb engine from the Slö, the reverse-reverb character of the Lore, and the granular soundscape generation of the Fable.
Sources (6)
- Lüm Texture Engine, Walrus Audio
- Lüm Texture Engine, Walrus Audio
- Walrus Audio Lüm Texture Engine review, MusicRadar, 2026-09-05
- Walrus Audio Lüm Texture Engine Granular Reverb, Pedal of the Day, 2025-09-16
- Guitar Pedal X, Guitar Pedal X, 2026-07-09
- Walrus Audio launches the Lüm Texture Engine, MusicRadar, 2026-07-07
