In the guitar world a very famous pedal which largely defined the sound of seventies rock music. Actually a distortion-sustainer. The sustain transforms the plucking of guitar strings to a somewhat screaming, violin-like sound. Has been used by bands like Sonic Youth, The White Stripes and Pink Floyd. Still popular and affordable. Cool effect on fiddle to: produces a very raw sound in the low range, and has some nice but screamy influence on the high range.