Prince was well known for using effects pedals, in particular Boss effects pedals.
For his first few albums and tours, Prince used amp distortion from his Mesa/Boogie Mark II and a Mutron Bi-phase phaser.
Prince started using Boss effects on the 1999 album and tour. His first set of Boss effects included Boss PSM-5 Power Supply & Master Switch, Boss SD-1 Super Overdrive, Boss BF-2 Flanger, Boss DM-2 Delay, Boss VB-2 Vibrato and Boss OC-2 Octave. He also used a Vox V846 wah on the 1999 album and a Dunlop Cry Baby on the tour.
Prince made small changes to this board over the course of his career but kept to this basic configuration. It is likely that he had multiple similar pedalboards. He switched the Boss DM-2 for a DSD-2 Digital Delay/Sampler then DD-3 Digital Delay. His main wah from 1986 ti 1998 was a vintage Colorsound Wah. In the early 1990s, he switched the SD-1 for a MT-2 Metal Zone and later added a DS-2 Turbo Distortion. The MT-2 was later switched for a BD-2 Blues Driver.
Prince also used rack effects from the late 1980s to the early 2000s. These were primarily a Roland GP-16 and a Zoom 9030, controlled by Roland EV-5 and Roland FC-100 controllers.
The Colorsound wah was eventually replaced by a Dunlop Cry Baby and Prince briefly used a Dunlop Rotovibe. In the 2000s, Prince introduced a Digitech Whammy, a Line 6 Modulation Modeller and a MXR Micro Amp.