The Ultimate Overdrive is a Tubescreamer based circuit with quite a few added perks. We've added a 6 position selector switch which allows you to click your way through six different gain stages and dynamics of the Ultimate Overdrive. Some of these changes are subtle and some of them are rather drastic.
However you won't be disappointed. If that's not enough there is a separate switchable clean booster that can be used with or without the Overdrive side of the pedal.