The Roland/Boss Dr. Sample SP-303 is a digital sampler from Roland based upon the Roland MS-1 Digital Sampler & Boss SP-202 Dr. Sample. The SP-303 was revamped and redesigned in 2005 and released as the SP-404.
The SP-303 itself provides up to three minutes and twelve seconds of sampling. The sample time can be expanded by the use of SmartMedia cards (8MB-64MB supported). The SP-303 features twenty-six internal effects that can be applied to samples and external sources as well. It also has a built-in sequencer. The SP-303 is often praised for its unique sound qualities. Frequent SP-303 user Dibiase said of the sampler, "The difference between the 303 and SP-404 is that the vinyl sound compression sounds way different in the 303. It has a grittier sound."
While the SP-303 Dr. Sample may lack some of the features seen on other hip hop production samplers such as the Ensoniq ASR-10 and the Akai MPC it also has many unique features. It has been used live and in the studio by artists such as Animal Collective, Panda Bear, Four Tet, Madlib and J Dilla. Dilla famously used only the SP-303 and a 45 record player to create 29 of the 31 tracks from Donuts while hospitalized. The SP-303 has a pattern sequencer, where loops and patterns can be programmed.