Walrus Audio took three of their most interesting pedals — the Slö, Lore, and Fable — threw them in a blender, and came out with something that’s earned its own permanent spot on the roster.
The Walrus Audio Lüm is a granular reverb that doesn’t just wash your signal in ambience. It fractures it into tiny grains and wraps those fragments in different textures depending on where you set the controls. The basics are familiar: Mix, Decay, Filter. The X and Stretch knobs are where it gets weird.
Three modes, three personalities.
- Mode I is Grain Cloud. Dual granular taps reading from a feedback delay line, with the X knob controlling grain size — basically how often you hear those little glitchy artifacts. Stack it with other modulated or wet effects and it starts sounding like your amp is dreaming.
- Mode II is Grain Verb. Same idea, but the grains are pulled from the delay memory of a reverb algorithm instead. The result is denser, more washed out — like the grains took a bath in reverb before reaching your ears. X still controls grain size. Pro tip: put this mode before a high-gain pedal and watch your solos turn into landscapes.
- Mode III is Forward/Reverse Verb. A forward reverb feeding into a reverse reverb, creating this playful ping-pong interaction between the two. Stretch controls how fast or slow that interaction happens. X controls the reverse reverb’s decay. It’s the mode that feels least like a pedal and most like a trick.
The deeper controls.
The Stretch Engine shifts the global sample rate from half-speed to double, which changes how everything interacts — grain size, reverb decay, filter tone. Crank it down for slow, noisy textures. Speed it up for clean, short reverbs.
The Moment control lets you hold a footswitch and automate any of the five knobs to a target position, then release and snap back. It’s knob animation in real time, and it makes the pedal feel alive under your foot. The Ramp switch (hidden in the bypass + mode toggle) lets you choose glide time between 10ms, 1000ms, or 5000ms — instant, slow, or glacial.
Three onboard presets (red, green, blue) with seamless fading between them, so you don’t lose your carefully crafted sounds mid-set. Trails mode for natural decay when you bypass, or instant cut if you want things to stop on a dime.
The bottom line.
The Lüm is for blissed-out passages, deep washes of ambience, and the kind of textures that make you forget you’re playing a guitar. It’s built by people who love chasing sounds, and you can hear that in every mode. Grainy, glitchy, lush, or straight-up chaotic — it’s a compact box that thinks it’s a much bigger system.
