Back in 1984, this beast became Roland's first guitar synth with patch memory, letting players store and recall sounds on the fly— a game-changer for live performances when hexaphonic pickups were still bleeding-edge tech.
Built around a fully polyphonic analog engine borrowed from the JX-3P, it delivers six voices, each tied to a guitar string via pitch-to-voltage conversion. Per-voice setup includes two DCOs—one with saw, pulse, and square waves across 16', 8', and 4' ranges, the other adding cross-modulation and sync for wild timbres—routed through a resonant 24dB lowpass VCF, a fixed highpass filter, and a VCA, all shaped by a versatile ADSR envelope that can target pitch, filter, or mod depth. A shared LFO handles vibrato or PWM, while onboard chorus adds lush depth; controls live on a hefty 26-pound pedalboard with footswitches for 64 battery-backed patches (eight banks of eight), basic editing, hold, and bank shifts, or plug in the PG-200 for knob-twiddling precision. It spits MIDI out too, so your guitar can boss external synths around.
Players loved the thick, versatile tones that fixed the GR-300's tracking quirks, though the floor-pedal editing felt clunky without the programmer, and string-specific latency took practice to tame—still, it's a vintage holy grail for hybrid guitar-synth rigs.
