ROLAND GR-100 FLOOR GUITAR SYNTH

via this auction

"The Roland GR-100 is the least known of all the vintage Roland guitar synthesizers. If six fuzz pedals with six -12 dB low-pass filters can make a guitar synthesizer, then this is a guitar synthesizer. But Roland wisely decided to call the GR-100 an "electronic guitar,". I would have to say it is a fuzz box with an adequate filter and a very nice chorus and vibrato circuit.

The GR-100 Synth Engine:
In this way, it is very different from the GR-300. The GR-300 generates its hex-fuzz sound by using the hex-fuzz circuitry contained in the guitar controller. For example, the G-202 has a different hex-fuzz circuit than the G-808. And the G-707 has no hex-fuzz circuit at all. But none of that matters with the GR-100, as it has a slightly more sophisticated version of the G-303/G-808 hex-fuzz design.

The hex-fuzz in the GR-100 is smoother than what you hear with a GR-300, and it also has an additional sustain feature. With the mode switch in the down position (mode 1), you hear guitar only. In the middle position (mode 2) you hear the basic GR-100 hex-fuzz sound, and with the switch in the up position (mode 3) you hear the GR-100 hex-fuzz sound with an additional sustain/compression circuit. As a side note, the hex-fuzz circuit in the RC-1324 is designed to emulate this overdriven, mode 3 hex-fuzz sound."