Alternatives to the MXR Poly Blue Octave

Catalinbread Perseus

Shared character: mono synth, tight tracking, one octave

Catalinbread Octapussy

Shared character: mono synth, tight tracking, one octave

EarthQuaker Devices Bit Commander

Shared character: mono synth, tight tracking, one octave

EarthQuaker Devices Eqd-Bit

similar tone character

EarthQuaker Devices Bit Commander V2

similar tone character

Beetronics Swarm Fuzz Harmonizer

Shared character: mono synth, tight tracking, one octave

Pigtronix Octava

Shared character: tight tracking, one octave, mix

Pigtronix OCT2

Shared character: tight tracking, one octave

Beetronics Vezzpa

Shared character: extreme settings, tight tracking, one octave

Fairfield Circuitry The Unpleasant Surprise

Shared character: extreme settings, mono synth, one octave

MXR M103 Blue Box

“expanding on MXR's classic Blue Box with four independently controllable octave voices”

EarthQuaker Devices Data Corrupter

Shared character: mono synth, tight tracking, one octave

T-Rex Octavius

Shared character: tight tracking, one octave

Dunlop MXR SUB Machine

Shared character: mono synth, tight tracking, one octave

Pigtronix Octava Micro V2

Shared character: tight tracking, one octave, fuzz

Beetronics AB-ST

Shared character: fuzz

Spaceman Nebula (Gloss Steel)

Shared character: one octave, mix, fuzz