Electro-Harmonix is a New York-based company that makes high-end electronic audio processors and sells rebranded vacuum tubes. The company was founded by Mike Matthews in 1968. It is best known for a series of popular guitar effects pedals introduced in the 1970s and 1990s.During the mid-70s, Electro Harmonix had established itself as a pioneer and leading manufacturer of guitar effects pedals. These electronic devices were cutting edge technology and innovations.