For a long time, the Timmy, and its big brother, the Tim were build by Paul Cochrane, who amassed a waiting list that often exceeded a couple years. In fact, a used Timmy was worth more than a new one because you didn't have to wait. 

It was famous for both its grit and transparency, the holy grail of overdrives. 

This version of the pedal is produced by MXR in collaboration with Paul Cochrane. 

 What MXR says: MXR Timmy Overdrive. This pedal provides a huge, responsive range of gritty and textured tones that enhance the sound of your rig while preserving its fundamental character—and in an MXR mini housing, this pedal will free up some serious pedalboard space.

This pedal can be powered by a Dunlop ECB003 9-volt adapter, or the DC Brick™, Iso-Brick™, and Mini Iso-Brick™ power supplies (not included).

Timmy Players: Billy Gibbons (ZZ Top), Wayne Sermon, John Dyer Baizley, Daughter, Andy Othling, Time Mahoney, James Duke, Peter Honore, Efrim Menuck, Igoe Haefeli, Kevin Starrs, Audley Freed, Dann Huff, Ocean Alley, Greg Barnett, Al Schnier, Kenny Greenberg, Miku Nakamura, Chuck Garvey, Brian Wooten, Jesse Garcia, Robert Poss, Trevor Terndrup, Richard On, Steven Page, Ziv Tamari, Jason Whitehorn, Lady Lamb, JT Corenflos, Kyle Schonewill, Josh Weaver, Joab Eastley, Marcos Pintor, Todd Beene, Dusty Redmon, Hunter Walls, Nick Fontinakes, 

[Via Equipboard]