The Akai S20 (released in 1997) is a. Portable, 16-bit stereo phrase sampler and sequencer originally designed for live DJ performances and looping. It features 16 velocity-sensitive pads, a built-in 30,000-note MIDI sequencer, and up to 16MB of memory (yielding about 131 seconds of stereo sampling). Key Features & Specs. 16-bit linear stereo sampling at 32kHz, 16kHz, and 8kHz rates. 5.5 seconds, expandable up to 17MB using standard 72-pin SIMM modules. Built-in floppy disk drive for saving programs and samples. Tap tempo, “Beat-Loop” function (matches phrases to specified tempo), and a “Hold” mode for infinite loop playback. Comes with RCA USB midi Interface and Adapter.