Yamaha DX21
Digital programmable algorithm synthesizer

Yamaha DX21


Another step in making capable synthesis available to the consumer public, the DX21 was released in 1985, improving upon the 4op FM technology first found in the DX9.

699£ got you somewhat what the DX5 was for the original DX7: sound features comparable to having two DX9 engines stacked (with split and layer capabilities), better memory, and a chorus unit. Velocity sensitivity was also available via MIDI input. All in a more compact package, with full MIDI implementation and better overall controls.

Praised by the critics for being a well-thought machine and not just a cut on features of previous models, the price tag made it another success for Yamaha in the 80s.

Technical specs


61 keys

Sound source

FM tone generator (4 operators x A-B, 8 algorithms)

Simultaneous note output

Polyphonic: single 8 / dual 4 / split 4+4
Monophonic: single 1 / dual 1 / split 1+1

Memory capacity

32 voice internal RAM (alterable)
32 performance internal RAM (alterable)
128 voice ROM (reading only)

Connection terminals and interfaces

Output MIX/A, Output B (mono phone jack)
Output Phones (mono phone jack)
Control jack: foot switch, foot controller
Cassette port
Breath control

Dimensions and weight

909w x 82h x 270d (mm) / 35.8” x 3.2” x 10.6”
8Kg / 17.6lbs


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