Roland launched the SP-404 in 2005 as part of its SP family of performance samplers: a small, pad-driven box that records and triggers samples instantly and passes them through a bank of characterful effects, from filters and delays to deliberately gritty processors. The SP-404SX followed in 2009 with 44.1 kHz/16-bit sound and 29 DSP effects. The SP-404MKII, announced in October 2021, added an OLED screen, 16 GB of internal storage, battery operation and effects named Vinyl Simulator, Cassette Simulator and Lo-fi.
Its speed, and its resample function, which records a pattern with the effects printed into a new sample, made it a staple of beat culture; Roland celebrates 404 Day around 4 April each year. In jazz lo-fi it is prized for adding dust, wobble and warmth in a few button presses.