Updated May. 2, 2022

Fuzz and octave (up or down) is a match made in Rock’n’Roll Hell (in a good way!) – yes because the results aren’t exactly heavenly, are they?

The MXR Poly Blue Octave takes this combo to the next level, with a circuit that offers not one, not two but FOUR separate polyphonic octaves (two up and two down) married with the classic MXR Blue Box fuzz – with a bunch of extra cool features (including modulation) thrown in for good measure.

Each octave – one octave down, two octaves down, one octave up, and two octaves up – is polyphonic and has its own knob, allowing to precisely set its volume in the mix. “Polyphonic,” for the uninitiated, means that it can transpose more than one note at a time, unlike similar old effects, but a Mono switch lets you convert the circuit into one of those vintage “octavers,” with their gritty analog tone.

This mode opens up a couple of inspiring vintage settings when only one octave is used, reminiscent of the raw personality of the MXR Vintage Bass Octave (with only the one octave down on) or the Octavio Fuzz (with only the one octave up activated).

The Dry knob is quite essential in a pedal of this kind and allows to reintegrate the clean signal to bring back some “reality” in this transposed sonic equation.

In Poly mode, the fuzz is applied to all five signals and can be adjusted using the Dry knob after pressing and holding the Fuzz button.

As if this wasn’t enough, this pedal also features a dual modulation circuit that adds a Leslie effect in Poly mode (also applied to all 5 channels) and a Phase 90-type phaser in Mono mode. The Mod knob sets the effect’s rate (off at zero).

An Exp In allows control of several parameters via expression pedal.

The MXR Poly Blue Octave is a compact and unusual beast that can do a lot of different things – have a listen to all the cool tones it can produce in the videos below.

MXR® POLY BLUE OCTAVE M306, Builder’s Notes

The MXR Poly Blue Octave brings modern and classic pitch-shifting styles together with fuzz and modulation to create the ultimate octave pedal for tonecrafters and sonic seekers.

The Poly Blue Octave features four separate octave divisions—one octave down, two octaves down, one octave up, and two octaves up—and you get to control the level of each in the mix. Each is polyphonic by default, which means they sound just as amazing with chords as they do with single note passages. Your dry signal gets its own level control, as well, so you can dial in the perfect blend of pitch-shifted tones.

The Mono switch takes you back to the gritty, monophonic tones of analog style pitch shifters. In this mode, the sub-octave signals have the warm vibes and raw personality of a pedal such as the MXR Vintage Bass Octave, while the higher octave signals resemble the Octavio Fuzz with its fuzz intensity dialed all the way back.

The Poly Blue Octave comes equipped with an unruly fuzz that’s inspired by the classic MXR Blue Box™ Fuzz. Applied to all five signals, the fuzz volume can be adjusted using the Dry knob after pressing and holding the Fuzz button. When used with the sub-octave signals, the fuzz sounds thick and subterranean. Over the higher pitched signals, the fuzz is searing and synth-like. Run them all at the same time for a choir of thunder and lightning.

For infusing your octave tones with an alluring sense of motion, from thick and syrupy to frenzied and frantic, the Poly Blue Octave features a dual-mode modulation effect. In polyphonic mode, the effect provides an uncanny simulation of the famous Leslie effect, and while In monophonic mode, it provides classic swirls and swooshes inspired by the Phase 90. Like the fuzz effect, the modulation applies to all five signals when engaged. The Mod knob adjusts the rate of the effect—when you want it off, just roll the Mod knob back fully counterclockwise.

Through the EXP jack, the Poly Blue Octave allows you to control various settings with an expression pedal such as the Volume (X)™8 Pedal or an off-board switch such as the MXR Tap Tempo Switch to sweep between two different knob and switch configurations or toggle the fuzz and mono modes on and off.

The MXR Poly Blue Octave delivers high-performance pitch shifting, fuzz, and modulation in a ruggedly reliable housing with true bypass switching. Put this into your signal chain, and open up new sonic frontiers.