The Klon Centaur in an overdrive guitar pedal designed by Bill Finnegan with the help of 2 MIT Electronic Engineers between 1990 and 1994. The initial idea was to improve the TubeScreamer transient response and the midrange-bass frequencies in order to create a big open sound with a hint of tube clipping: the so-called transparent overdrive.
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The design process took more than 4 years and the result was a mythic $329 hand build pedal that was running in production for 15 years. Nowadays the original models are highly appreciated, you just need to check eBay to see how high it goes.
