The Roland JD-990 Super JD is a module version of Roland JD-800 synthesizer with expanded capabilities, which was released in 1993.
JD-990 is a multitimbral synthesizer utilizing 'wave-table' sample-based synthesis technology. It is equipped with 6 MB of ROM containing wavetables, four sets of stereo outputs that are assignable to individual, internal, instruments, and standard MIDI in/out/through ports.
JD-990 has a large LCD display and programming takes place through a keypad on the front panel of the unit. The unit can generate multi-timbral sounds reminiscent of the vintage analogue synthesizers but is also capable of generation of modern digital textures.
There are several expansion boards available for JD-990 that can be installed in the provided expansion slot in the chassis of the unit.