MXR Poly Blue Octave Fuzz & Modulation Pedal

The MXR Poly Blue Octave combines polyphonic pitch shifting, fuzz, and modulation in a single pedal. Four octave divisions — one and two octaves down, one and two octaves up — each have their own level control, and all are polyphonic by default, meaning they track chords as cleanly as single notes. Your dry signal has its own level control too, so you can blend everything to taste.

A Mono switch shifts the sub-octave signals into the warm, gritty character of analogue-style pitch shifters, while the upper octave signals take on the raw personality of the Octavio Fuzz with fuzz dialled back. The built-in fuzz — inspired by the classic MXR Blue Box™ — applies across all five signals simultaneously: thick and subterranean on the lows, searing and synth-like on the highs, or run them all together for a full wall of sound.

A dual-mode modulation effect adds motion to your octave tones: polyphonic mode simulates a Leslie-style effect, while monophonic mode delivers Phase 90-inspired swirls and swooshes. The Mod knob controls rate, and rolling it fully counterclockwise disengages the effect. An EXP jack allows connection of an expression pedal or off-board switch for real-time control of knob configurations and toggling fuzz and mono modes.

True bypass switching, rugged construction, and 9V AC adapter power (battery not supported) round out the package.