Pitch Modulation

Basics of Pitch Modulation Pedals for Guitar

Pitch Modulation, used by countless guitarists, has been present in the music industry since the 1960's. Chorus, Flanger, and Phaser are the most common "categories" for pitch modulation pedals. Although not necessarily true pitch modulation pedals, wah (or wah-wah) and pitch shift pedals also fall into this family.

Chorus, Flanger, and Phaser (or Phase Shifter) Pedals are simply devices that clone a guitar's signal, vary (modulate) this cloned signal's frequency (pitch), phase (timing), and amplitude (volume) and mix it back in with the original unprocessed (dry) signal. The delay time between the original signal and the "cloned" signal has a significant impact on the sonic results of the "mixture". Although this is an oversimplified explanation, it provides you a good starting point for getting a basic understanding on how pitch modulation pedals function.

Wah (or Wah-Wah) Pedals were originally intended to mimic the sound of a human voice. They are often referred to as "bandpass" filters.....basically sound filters that allow frequencies within a certain range and reject frequencies outside of that range. These select frequencies are what you hear when you rock the pedal back and forth, creating that unmistakeable "wah" sound.

Pitch Shifters (not to be confused with "Phase Shifters") are very simple to understand. They essentially take a sound (individual pitch) and either raise it or lower it by a specific musical interval (4th, 5th, octave, etc.). This musically "altered" tone is typically heard at the same time as the original sound.....no delay.......so it sounds like the same instrument playing two different notes at the same time. This technology is what the "POG" and "Whammy" Pedals are built around.