DigiTech Whammy
The DigiTech Whammy is a treadle-controlled digital pitch shifter pedal introduced in 1989. It uses a licensed IVL Technologies algorithm to shift pitch up to two octaves. Early models were monophonic and produced artificial, wobbly artifacts on chords. Later models improved chord tracking accuracy. It was developed by DOD Electronics (branded as DigiTech), a company founded in 1974.