I've bought one secondhand in the
late eighties from Jo Bogaert (Technotronic,
Nux Nemo) but I don't think he was the owner.
If I can remember, did he the sale for a
friend.

After a few months perfectly working,
the Poly Ensemble devision didn't work anymore.
As I wasn't sure whether it was my guitar
or the synth who was broken,
I went to Chris Whitley in Latem,
who had a Gr 700 system.
But his guitar couldn't plugged in my
GR 500 and/or vice versa, so I
couldn't check ...

I sent the GR500 via Vic Keersmaekers to
Roland Benelux.

After several weeks I got the GR 500 back,
but never worked perfectly anymore .....
It was a great machine, with fantastic warm
sounds, ..... but a little unstable and restrict
what concerns sounds.

Overview

Thanks to Roland, guitars and synthesizers have
had a long working relationship together.
The GR-500 is a vintage guitar controlled synthesizer
before there was MIDI too!

It was the first synth of this kind that Roland had
ever produced, back in 1977.
The synthesizer module itself was a simple analog
affair with Bass, Solo Synth, and String sounds
based on previous Orchestral and analog mono-synths
from Roland. There are plenty of sliders to
adjust the VCO, VCF, VCA, and LFO sections,
but no memory to store your edits.

The synth module is controlled by a
"highly modified" guitar.
Notice all those knobs on the guitar pictured at the right.
It utilized a special pickup system that connected
to the synth module via Roland's own 24-pin
interface and controlled it using CV/GATE signals
generated by the guitar's pickup system while
playing the guitar.

In addition to the modified pickup, there were
magnets under the face of the guitar that could
increase its sustain.
Performance accuracy was "iffy" but good for
1977 and pre-MIDI.

As a piece of guitar-synth history, the GR-500
makes an excellent collectors item and may
come in handy for the occasional growl or a
strummed analog sound effect.

It has been used by Tangerine Dream,
Mike Rutherford ofGenesis and Alex Lifeson of Rush.

Listen to some recordings of the Roland GR 500 bundled on the GR 500 Files project, at the Music page at the bottom.

Technical Info

Memory   None
Filter        Resonant Low pass
Effects     None
Control    CV/GATE Roland 24-pin interface to
                modified guitar / pickup system

Date         1977

Source www.vintagesynth.org