Walrus Audio Fathom Settings Guide
Walrus Audio's flagship multi-function reverb — four algorithms (Hall, Plate, Lo-Fi, Cave) with a dedicated Decay control, Mix control, and the x4 sub-oscillator switch that adds a low-frequency resonance beneath the reverb tail. The Cave algorithm produces a dense, unpredictable reverb texture used in ambient and post-rock contexts; the Lo-Fi setting adds bit-crushing and flutter to the reverb signal. The Fathom is positioned between the Boss RV-6 and the Strymon BigSky in terms of complexity and price, and is widely used by artists who want expressive reverb control in a professional but not boutique-priced enclosure.
The best Walrus Audio Fathom settings start with: Decay at 5/10, Mix at 4/10, Tone at 5/10, Mod at 3/10, Algorithm at 0/10. Adjust from there based on your amp, guitar, and room volume. For Post-Rock / Ambient: Decay 8/10, Mix 6/10, Tone 6/10, Mod 5/10, Algorithm 3/10.
⚡ Start Here — Recommended Settings
| Control | Starting Position | Range |
|---|---|---|
| Decay | 5/10 | Short Tail → Infinite Hold |
| Mix | 4/10 | Dry Only → Wet Only |
| Tone | 5/10 | Dark Warmth → Bright Air |
| Mod | 3/10 | Static → Heavy Modulation |
| Algorithm | 0/10 | Hall → Cave |
These are universal starting points. Adjust based on your amp, guitar, and room. Scroll down for genre-specific settings and artist-documented positions.
What Each Control Does
Recommended Starting Settings
Safe starting positions for any style. Adjust from here based on your amp and room.
All values on a 0–10 scale. These are starting points — fine-tune by ear.
Settings by Genre
Cave algorithm, high Decay — the Fathom's signature ambient setting. The Cave algorithm produces an unpredictable, dense reverb tail with character unique to Walrus Audio's design; at Decay 8 the tail is long enough to blend sustained notes into a continuous pad. Mod at 5 adds pitch movement to the tail. This is the setting for ambient and shoegaze guitar where the reverb is as important as the dry signal.
Plate algorithm, moderate Decay — the Fathom as a standard studio plate reverb. The Plate algorithm produces a smooth, even reverb character suitable for clean and overdriven guitar in a mix context. Decay 5 and Mix 3 keep the reverb supportive rather than dominant; this is the most utilitarian Fathom setting for recording.
Lo-Fi algorithm, darker Tone — the Fathom's bit-crushed, saturated reverb character used in indie and lo-fi contexts. The Lo-Fi algorithm degrades the reverb signal with aliasing and flutter; combined with Tone 4 (darker) and Mod 6 (heavy pitch wobble) the result is a worn, cassette-era reverb texture.
Hall algorithm, conservative Mix — the Fathom as a live reverb replacing an amp's spring reverb. Decay 4 and Mix 3 produce a supportive room character without dominating the dry signal; the Hall algorithm is the most universal and mix-friendly of the four. For live use where the reverb should add space without calling attention to itself, this is the starting point.
Tips & Common Mistakes
- The x4 sub-oscillator switch (the small toggle on the right of the pedal) adds a low-frequency resonance beneath the reverb tail that produces a synth-pad-like quality to sustaining notes. Use it sparingly on individual notes rather than on chord playing — the sub-oscillator adds a fixed pitch character that can create dissonance against chord changes if left engaged during rhythm playing.
- The Fathom's Mix control at maximum (wet-only) allows it to be used in a parallel effects loop without volume increase from the dry signal — ideal for guitarists who want reverb as an independently controlled element. In a series loop, keep Mix between 3 and 6 to maintain the dry signal presence.
FAQ
Walrus Audio Fathom — Common Questions
Best starting settings for Walrus Audio Fathom: Decay at 5/10, Mix at 4/10, Tone at 5/10, Mod at 3/10, Algorithm at 0/10. Adjust from there based on your guitar, room, and playing style.
For Post-Rock / Ambient: Decay 8/10, Mix 6/10, Tone 6/10, Mod 5/10, Algorithm 3/10. Cave algorithm, high Decay — the Fathom's signature ambient setting. The Cave algorithm produces an unpredictable, dense reverb tail with character unique to Walrus Audio's design; at Decay 8 the tail is long enough to blend sustained notes into a continuous pad. Mod at 5 adds pitch movement to the tail. This is the setting for ambient and shoegaze guitar where the reverb is as important as the dry signal.
For Studio Reverb: Decay 5/10, Mix 3/10, Tone 5/10, Mod 2/10, Algorithm 1/10. Plate algorithm, moderate Decay — the Fathom as a standard studio plate reverb. The Plate algorithm produces a smooth, even reverb character suitable for clean and overdriven guitar in a mix context. Decay 5 and Mix 3 keep the reverb supportive rather than dominant; this is the most utilitarian Fathom setting for recording.
Decay: Reverb tail length. At maximum, the Fathom sustains indefinitely (freeze mode). (Short Tail to Infinite Hold). Mix: Blend between dry guitar signal and reverb signal. (Dry Only to Wet Only). Tone: Reverb EQ — dark settings warm the tail, bright settings add shimmer and air. (Dark Warmth to Bright Air). Mod: Modulation amount applied to the reverb tail. Adds pitch movement and chorus-like character to the tail. (Static to Heavy Modulation). Algorithm: Four algorithms: Hall, Plate, Lo-Fi, Cave. (Hall to Cave)
The x4 sub-oscillator switch (the small toggle on the right of the pedal) adds a low-frequency resonance beneath the reverb tail that produces a synth-pad-like quality to sustaining notes. Use it sparingly on individual notes rather than on chord playing — the sub-oscillator adds a fixed pitch character that can create dissonance against chord changes if left engaged during rhythm playing. The Fathom's Mix control at maximum (wet-only) allows it to be used in a parallel effects loop without volume increase from the dry signal — ideal for guitarists who want reverb as an independently controlled element. In a series loop, keep Mix between 3 and 6 to maintain the dry signal presence.
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