Poly Blue Octave (M306)

The Poly Blue Octave is an MXR octave pedal that can add up to four voices to your own tone: two octaves below and two above. The knobs mix the dry signal, the octaves underneath and the octaves on top, separately or all at once. A switch chooses between polyphonic and monophonic. In polyphonic mode chords stay intact; in monophonic mode the pedal follows single notes, and a little octave up then gives just a bit more definition in the mix.

On top of that come two extras. The Mod function adds a swirling modulation that sits between a phaser and a rotary speaker. In polyphonic mode it recalls a Leslie, in monophonic mode more the swoosh of a Phase 90, and with some reverb behind it you get an organ-like sound. The fuzz is a lot rougher: it goes fully open in one go and has no control of its own. It is handy if you rarely use fuzz, but if you want a proper fuzz you are better off adding a separate pedal. If you know the old Blue Box: this pedal sounds clearly different.

With an expression pedal connected, you move between two settings with your foot. Saving is not possible; you dial each sound in again by hand. It works well on bass, with active and passive pickups, and it tracks without glitches. The housing is the standard MXR size. Batteries do not fit, the power socket sits on the right-hand side, and the fuzz and mono buttons feel a little cheap and need a firm press.

If you are after an octave pedal that tracks cleanly on both guitar and bass and want more than a single octave added, there is a lot here. If it is mainly the fuzz you want, look further.