The Warm Audio Mutation Phasor II is a Warm Audio phaser pedal, currently around $139.99. Close alternatives include the Catalinbread Many Worlds and the Rotosound RKH1 The King Henry Phaser. It pairs well with the Bad Cat Cub and the Cornell Romany 10 Tweed 10 watt Tube.
Warm Audio Mutation Phasor II
Warm Audio · pedal
The Warm Audio Mutation Phasor II reproduces the Musitronics Mu-Tron Phasor II, a legendary 1970s phaser circuit prized by collectors and funk, psychedelic, and progressive rock players for a deeper, more envelope-responsive sweep than most conventional phasers offer. Mu-Tron's original units have become rare and expensive vintage collector pieces, making faithful clones like Warm Audio's an important way for modern players to access that specific, historically significant sweep character without hunting down and paying vintage prices for an aging original. Warm Audio built its reputation on accessible, accurate recreations of iconic vintage studio and effects hardware, and this phaser continues that mission within the modulation effects category specifically.
What stands out
“Players chasing that specific 1970s Mu-Tron phaser character, deeper and more dynamically responsive than a typical phaser, seek out clones like the Mutation Phasor II specifically because original Mu-Tron units are rare, expensive, and inc…”
— from the community notes
“Mu-Tron's original units have become rare and expensive vintage collector pieces, making faithful clones like Warm Audio's an important way for modern players to access that specific, historically significant sweep character”
— from the listing
“The Warm Audio Mutation Phasor II reproduces the Musitronics Mu-Tron Phasor II, a legendary 1970s phaser circuit prized by collectors and funk, psychedelic, and progressive rock players for a deeper, more envelope-responsive sweep than most…”
— from the listing
“more envelope-responsive sweep than most conventional phasers offer”
— from the listing
“The original Mu-Tron Phasor II holds a genuinely important place in vintage effects history, and Warm Audio's decision to clone it specifically, , speaks to how significant that particular sweep chara…”
— from the reviews
Trade-offs
“and many players run it after any drive or fuzz pedals to let the phaser sweep an already-shaped tone”
— from the community notes
- phaser
- funk
- psychedelic
- envelope
- particular sweep character
- historically significant sweep character
- already shaped tone
- stage
Price updated Oct 24, 2026
Genres the Warm Audio Mutation Phasor II is commonly used in
- Progressive Rock
- Electronic
- Funk
Amps that pair well with the Warm Audio Mutation Phasor II
Bad Cat Cub
Bad Cat
22% matchshapes the dynamic responseShapes how the tone responds to picking dynamics rather than its frequency or gain. (dynamic → compressed)
What Bad Cat Cub brings here leans toward harmonically rich — that's worth building a pairing around
Comes later in the signal chain
Cornell Romany 10 Tweed 10 watt Tube
Cornell
21% matchshapes the dynamic responseShapes how the tone responds to picking dynamics rather than its frequency or gain. (dynamic → compressed)
Cornell Romany 10 Tweed 10 watt Tube leans this dynamic tone toward compressed, which it doesn't make on its own
Comes later in the signal chain
Ceriatone British Style 2525
Ceriatone
tonal matchComes later in the signal chain
Into a dynamic tone, Ceriatone British Style 2525 brings a pull toward compressed that's missing
Vox AC30S1 OneTwelve 30W 1x12 Combo
Vox
tonal matchComes later in the signal chain
Into a dynamic tone, Vox AC30S1 OneTwelve 30W 1x12 Combo brings a pull toward compressed that's missing
Fryette Power Station 100
Fryette
tonal matchComes later in the signal chain
Fryette Power Station 100 leans this dynamic tone toward compressed, which it doesn't make on its own
Kustom HV30 Tube
Kustom
tonal matchComes later in the signal chain
Kustom HV30 Tube leans this dynamic tone toward compressed, which it doesn't make on its own
Mesa/Boogie Stiletto Deuce Stage II
Mesa Boogie
tonal matchComes later in the signal chain
Mesa/Boogie Stiletto Deuce Stage II leans this dynamic tone toward compressed, which it doesn't make on its own
Friedman PT-20
Friedman
tonal matchComes later in the signal chain
Friedman PT-20 leans this dynamic tone toward compressed, which it doesn't make on its own
Pedals that stack with the Warm Audio Mutation Phasor II
Origin Effects RevivalDrive
Origin Effects
22% matchshapes the dynamic responseShapes how the tone responds to picking dynamics rather than its frequency or gain. (dynamic → compressed)
Into a dynamic tone, Origin Effects RevivalDrive brings a pull toward compressed that's missing
Comes earlier in the signal chain
J. Rockett Archer Ikon
J Rockett
21% matchshapes the dynamic responseShapes how the tone responds to picking dynamics rather than its frequency or gain. (dynamic → compressed)
Into a dynamic tone, J. Rockett Archer Ikon brings a pull toward compressed that's missing
Comes earlier in the signal chain
JHS Lucky Cat Delay limited edition
JHS Pedals
11% matchsits in the right chain slotPlaced for where it does its job cleanly in the chain, not for a tonal interaction with the anchor.
Keep Warm Audio Mutation Phasor II's dynamic voice out front: JHS Lucky Cat Delay limited edition goes after Warm Audio Mutation Phasor II in the signal chain so its pristine voice doesn't muddy it — goes in the amp's FX loop (or last, into a clean amp)
Comes later in the signal chain
Echoplex EP-3
Echoplex
10% matchsits in the right chain slotPlaced for where it does its job cleanly in the chain, not for a tonal interaction with the anchor.
Echoplex EP-3's analog warmth voice goes after Warm Audio Mutation Phasor II in the signal chain — it's not there to compete with Warm Audio Mutation Phasor II's own dynamic character — goes in the amp's FX loop (or last, into a clean amp)
Comes later in the signal chain
DigiTech DOD Compressor 280
Digitech
tonal matchComes earlier in the signal chain
DigiTech DOD Compressor 280 leans this dynamic tone toward compressed, which it doesn't make on its own
DigiTech XBS Bass Squeeze
Digitech
tonal matchComes earlier in the signal chain
DigiTech XBS Bass Squeeze leans this dynamic tone toward compressed, which it doesn't make on its own
Fairfield Circuitry 20% More
Fairfield Circuitry
tonal matchComes earlier in the signal chain
Fairfield Circuitry 20% More leans this dynamic tone toward compressed, which it doesn't make on its own
Tech 21 CompTortion
Tech 21
tonal matchComes earlier in the signal chain
Into a dynamic tone, Tech 21 CompTortion brings a pull toward compressed that's missing
Cheaper alternatives
MXR ZW90 Wylde Phase
MXR
55% similarityShared character: phaser, vintage charm, stage
MXR Deep Phase
MXR
55% similarityShared character: phaser
Blaxx BX-Phaser
Blaxx
54% similarityShared character: phaser, vintage charm
Behringer VP1B
Behringer
52% similarityShared character: phaser, vintage charm, studio
CNZ Audio SPH-20
Cnz Audio
51% similarityShared character: phaser, vintage charm, stage
Simple Sam Faze-It Phase
Simple Sam
49% similarityShared character: phaser, stage
Boutique & premium upgrades
Death By Audio Moonbeam
Death By Audio
52% similarityShared character: phaser, stage
Fredric Effects West Germany Tremolo
Fredric Effects
49% similaritySimilar voicing: spring
Alexander Pedals Luminous Phaseshifter
Alexander Pedals
91% similaritysimilar tone character
Spaceman Mission Control: Expressive Audio System
Spaceman
90% similaritysimilar tone character
EarthQuaker Devices Grand Orbiter
EarthQuaker Devices
90% similaritysimilar tone character
Similar charactersee all similar tone character →
Catalinbread Many Worlds
Catalinbread
60% similarityShared character: phaser, stage
Rotosound RKH1 The King Henry Phaser
Rotosound
58% similarityShared character: phaser
Roland Corp US PH-3 Phase Shifter
Roland
58% similarityShared character: phaser, stage
Alchemy Audio Phasor II
Alchemy Audio
57% similarityShared character: phaser, original, vintage charm
AA Audio Rotary 3 toggle Phase, Vibe
Aa Audio
57% similarityShared character: phaser
Fender Waylon Jennings Phaser
Fender
54% similarityShared character: phaser, studio, stage
See all alternatives to the Warm Audio Mutation Phasor II (cheaper + boutique) →
Questions people ask
What are good alternatives to the Warm Audio Mutation Phasor II?+
The closest matches in character are the Catalinbread Many Worlds, the Rotosound RKH1 The King Henry Phaser, the Roland Corp US PH-3 Phase Shifter. Budget picks: MXR ZW90 Wylde Phase, MXR Deep Phase, Blaxx BX-Phaser. Boutique upgrades: Death By Audio Moonbeam, Fredric Effects West Germany Tremolo, Alexander Pedals Luminous Phaseshifter.
What pairs well with the Warm Audio Mutation Phasor II?+
Strong matches from rig and tone-complementarity evidence: Bad Cat Cub, Cornell Romany 10 Tweed 10 watt Tube, Ceriatone British Style 2525 — What Bad Cat Cub brings here leans toward harmonically rich — that's worth building a pairing around.
How much does the Warm Audio Mutation Phasor II cost?+
Around $139.99 (live listing price, updated Oct 24, 2026).
Compare
- vs Alexander Pedals Luminous Phaseshifter
- vs Artec SE-VPH Vintage Phase Shifter
- vs Spaceman Mission Control: Expressive Audio System