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A flanger with plenty of range and hidden depths, the Polychrome is another classy addition to Walrus Audio’s modulation lineup.

Classy sounds and lots of tweaking potential.

Smart footswitch for momentary flanging.

Walrus Audio (opens in new tab) ’s Polychrome is an intuitive and powerful flanger pedal. The only real obstacle standing between it and your pedalboard (opens in new tab) is when it is considered in context with other modulation effects. Indeed, why use the Polychrome over the Lillian phaser or vice versa? 

For many players, choosing between flanger, phaser or chorus pedal (opens in new tab) can be a moveable feast, and there are enough in-between sounds here to complicate matters, including a rotating speaker-style effect, pitch vibrato and pseudo-chorusing sounds. 

The Polychrome offers a heady brew of modulation (opens in new tab) , with tones that verge from the subtle and classic to the experimental and plain weird.

Finding these tones is a breeze. The Rate knob can dial in modulation speeds between 0.1Hz and 8Hz. Those super-slow flange speeds take an age to unfold, while extreme settings have a similarly disorientating quality as a Leslie speaker. While the sine and triangle flange sounds are familiar, the random mode injects a little anarchy into proceedings, ideal for tonal off-roading.

Both the Depth and Sweep modes are interactive. The former sets the depth of the LFO and the filter sweep’s width, while the latter adjusts which frequency range the filter sweep is affecting. 

• Source Audio Mercury Flanger (opens in new tab) The Shadow setting dials in a more animated and intense flanging experience. Again, it's a perfect partner for dirty sounds and the place to be if spaceship and ray-gun sounds are on your agenda.

• Moog MF Flanger (opens in new tab) To our ears, the MF Flange recalls EHX's Electric Mistress - dial everything back, and you have a liquid chorus that's a dead ringer for Walking On The Moon.

Set it low and you can have a deep, aquatic whoosh, while setting it past noon returns the Polychrome to more classic flange sounds. Set the Depth to zero and D-F-V to noon and you can use the Polychrome as a notched filter, adjusting intensity to taste via the Feedback knob.

That brings us nicely to the Feedback control, which performs as you might expect, controlling the amount of signal that is fed back through the effect. At higher settings, you’ve got a flanging effect that’s ideal for EVH-style pyrotechnics, adding movement and vitality to overdriven guitar tones, and at lower settings, you can use the Polychrome as a stand-in or alternative to your chorus pedal.

Yes, there are heaps of modulation pedals out there. Right now, it seems that the phaser pedal is this year’s must-have effect. But if you need a high-quality flanger with range and an intuitive control setup, it’s hard to look past the Polychrome. It’s another classy design from Walrus Audio. 

We would have liked an expression pedal input or an input for an external tap tempo, but you can’t argue with the quality of the sounds, and the smart footswitch's momentary press-and-hold functionality is a welcome feature.

MusicRadar verdict: A flanger with plenty of range and hidden depths, the Polychrome is another classy addition to Walrus Audio’s modulation lineup.

“The pedal works really well with distortion in front of it for rich textured sound with a sense of movement about it. Traditional flanging aside, though, this is a fine source of varied modulation that include chorus-like tones, pitch vibrato and the aforementioned rotary speaker sounds. That D-F-V knob is your key to just how much effect you want.” Guitarist (opens in new tab)

“While the Polychrome offers a wide pallete of sounds, it excels at subtlety. Rather than just favor the noisy, brutish airplane sounds I associate with the flangers of my youth, this pedal excels at adding a warm neon glow without ever getting harsh. Once you get the hang of the controls, you can summon just about any flanger tone you could want, as well as excellent phaser- and chorus-like tones.” Premier Guitar (opens in new tab)

“In the life of a stompbox aficionado, it’s an increasingly rare occurrence to be able to say, “I’ve never heard this before”. Yet these words left our lips on several occasions, including one particularly glorious experience when we could discern upper partial harmonics sliding into fleeting moments of feedback during an arpeggiated chord sequence like they had a life of their own.” Guitar (opens in new tab)

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