A chorus pedal makes your solo sound like multiple guitars (or keyboards, or voices) playing in unison. An octave or pitch shifter pedal makes you sound like multiple players in harmony.
Pitch Changing Pedal Types
Octave and pitch shifter pedals are very specialized. Most are monophonic, meaning that they are intended to work for single notes and not for chords. Some octave pedals produce a sound that is one or two octaves below the original note, while others add a tone that is one octave above the original note. Some pitch shifters are can produce multiple voices, including thirds, fifths, and multiple octaves up or down.
So here are some pedals to consider when looking for an octave, pitch bender or harmonizer for guitar:
The Digitech Whammy DT Pitch Shift Effect Pedal is one of the most versatile pedals in this category. This is a true polyphonic pedal that lets you play with different tunings without retuning your guitar. The Whammy DT lets you drop or raise your tuning by seven half-steps or a full octave.
Electro Harmonix Micro POG Polyphonic Octave Pedal lets you six string guitar sound like a twelve string or your 4 string bass sound like an eight. It lets you go an octave up and an octave down and can handle chords, arpeggios, and single notes smoothly with no glitches.
The Boss OC-3 Super Octave was the first polyphonic octave pedal. The unit operates in three modes: OC-2 mode which produces notes one and two octaves down; Polyphonic Octave mode, which allows octaves to be added in specific note ranges (user selectable) while playing chords; and Drive Mode, which adds distortion to the octave voice. The OC-3 has separate inputs for guitar and bass.
The Boss PS-6 Harmonist offers four intelligent pitch shift effects, letting you create three voice harmonies in major and minor keys. It includes up to four octaves of pitch bending, as well as detuning. In Super Bend mode, you can bend notes or chords as you would with a guitar’s whammy bar, but to unbelievable extremes of up to two octaves up or down. In Detune Mode, you can get a sound similar to a chorus pedal on chords and arpeggios. Harmony Mode only works on single notes, but creates up to three voice harmonies using 3rds, 4ths, 5ths, 6ths, and octaves.
Rocktron Black Rose Octaver. Part of its boutique series of effects, featuring True Bypass circuitry, the Rocktron Black Rose Octaver adds a tone that is one octave below the notes you are playing. It tracks beautifully and provides ample control over the sound of the octave below signal, which can be changed from smooth to crunchy by the flip of its “Roots” switch, and adjusted with its mid frequency boost Fragrance control. You can route the original tone and the octave tone separately through separate amps and effects or you can merge them into a single output.
Dunlop JHOC1 Jimi Hendrix Octavio Fuzz Pedal. An oldie but a goody, the Jimi Hendrix Octavio pedal is a reproduction of the original octave up pedal enshrined in the Jimi Hendrix exhibit in the Rock and Roll Hall of Fame. This gives you the same fuzzed out octave up tones Jimi used on the Band of Gypsys: Live at the Fillmore East performance.