Boss SD-1 Super Overdrive
An overdrive pedal used by Prince from the 1999 era to the Diamonds and Pearls era. This pedal is a low-gain overdrive so it was almost certainly combined with his Mesa/Boogie Mark II amplifier to get the high gain sounds Prince is associated with. As Prince moved away from Mesa/Boogie amplifiers in the 1990s, he stopped using the SD-1. It can be heard on the guitar parts of Let's Go Crazy and Purple Rain and the drum parts of The Ballad Of Dorothy Parker and Hot Thing.