Roland GR-77B

The Roland GR-77B is a bass synthesizer. It was designed to be used with a G-77 bass guitar. Brownmark used a GR-77B with Prince, but had his own pickup built into an Alembic Spoiler, so he could avoid using the G-77 bass.

It is the bass version of the GR-700 used by Prince and Wendy Melvoin.