The Fulltone OCD is a landmark overdrive/distortion pedal that helped redefine the genre when it launched in 2004. As the first pedal to use a MOSFET operational amplifier, it delivered a more open, responsive tone that preserved the nuances of both player and instrument. Whether used as a clean boost, to push a tube amp into rich harmonic saturation, or as a standalone source of articulate distortion, the OCD remains remarkably versatile. Its ability to produce dynamic, amp-like overdrive made it a go-to choice for players across genres.

Operating at either 9V or 18V for increased headroom and punch, the OCD includes a HP/LP (High Peak/Low Peak) toggle for tailoring the response—choose between a punchy, mid-forward tone reminiscent of British amps or a more transparent character that keeps your core tone intact. Over eight revisions between 2004 and 2017, version 1.4 (released in 2009) stands out for its added Germanium diode, improved harmonic content, and more precise volume control. It's a modern classic that continues to earn its place on countless pedalboards.