Roland D-50 and D-550

The Roland D-50 was a polyphonic 61-key synthesizer produced by Roland. It was released in 1987.Its features include on-board effects, a joystick for data manipulation, and an intuitive layout design. The external Roland PG-1000 Programmer could also be attached to the D-50 for more complex manipulation of sounds.

The D-50 could be modified through the addition of a 3rd-party product (the Musitronics M-EX) to make it multitimbral. It was also produced in a rack-mount variant design, the D-550, with almost 450 user-adjustable parameters.