The GR-77B is a bass guitar synthesizer based on the Roland JX-8P synth engine. It is controlled using a MIDI bass with a 24-pin cable and can be edited using a PG-800 programmer. The guitar version is the GR-700.
Year Released: 1985
Preset Patches: 32
User Patches: 32
Screen: 4-character 7-segment LED display
Power Consumption: 27 watts
Weight: 12 kg
Dimensions: 690 mm x 375 mm x 155 mm