Roland GR-100

via this auction

"The Roland GR100 was developed as a system to electronically process sounds with the string vibrations themselves being the sound source. This was Rolands first guitar synth made in the 1970's and is now a collectors item.

HEXA distortion circuit makes it possible to get clean distortion which could not be experienced by electric guitar. The GR-100 is equipped with the HEXA Dis tortion circuit which can distort the string vibrations that are divided into six sound sources by the Divided Pickup. The sound distorted by the HEXA Distortion is clean, deep, and powerful, with a rich sustained sound and beautiful harmony could not be obtained by a regular distortion or over-drive device.

HEXA Filter, cutoff frequency, and resonance for powerful filtering effects Each sound source from the string passes through the HEXA Filter circuit of the GR-100 as well as the HEXA Distortion. HEXA Filter is preadjusted in accordance with the guitar tuning (E, B, D, A, G), low for the lower notes and high for the higher notes. Therefore, unlike using the graphic equalizer or the parametric equalizer, it is possible to balance the string sounds and create a versatile selection of sounds, from soft to hard, using the Cutoff Frequency and Resonance.

GR-100 is equipped with three effect controls, and one of them is the Filter Modulation. It enables you to add a "wow" effect onto the electronic sounds regardless of Cutoff Frequency or Resonance, and controls the picking power (stress) with the SENS control and the depth of the "wow" effect with the PEAK control.

The second effect control on the GR-100 is Vibrato. By turning the Touch Vibrato switch ON and OFF, a powerful vibrato effect quite different from a manual vibrato can be obtained. The third effect control is Stereo Chorus which deepens and broadens the sound.

As the electric guitar amplifiers are made for electric guitars, they are designed to raise and emphasize the higher range, resulting in a thin sound when recorded directly out from line. GR-100 has a wide range and shows outstanding performance without losing the true nature of the guitar sound, making it suitable even for studio work."

Toccata in D minor (Bach)-Ketil Strand-Roland GR-100/G-505 electric guitar

"This is a follow-up to my previous Toccata version played on my Axon AX100 guitar synth.
Some of the commenters on the Toccata video asked me to do a guitar version without the synth organ sound, so here it is. Instead I'm using a pretty rare device this time; the Roland GR-100 Electronic Guitar, which is a "hexaphonic fuzz" unit that is controlled from my Roland G-505 "synth controller" guitar. It creates a soft "fuzz"-type overdrive, but it's hexaphonic, so you can play any chord and hear all the notes clearly, unlike a regular fuzz/overdrive pedal. This was one of Roland's early GR series of "guitar synth" units that came out in the early 80's I think (pre-midi), but unlike the other Roland GR products this isn't really a synth, it's more like 6 fuzz pedals in one.. It's a fully analog guitar signal, but it uses the guitar's built-in hexaphonic pickup instead of the regular pickups. The GR-100 unit also has built-in Filter, Vibrato and Chorus effects, but I'm not using these here. The "hex. fuzz"is controlled from the Roland G-505 guitar's built-in controls and switches.
Although the built-in hex. pickup on my Roland guitar basically is the same type as Roland's current GK pickups, it's not compatible with current guitar synths because of the different type of connectors. The Roland G-505 uses a large 24-pin connector that was discontinued years ago, but today Roland and Axon synth guitar systems uses a much more convenient 13-pin connector. So that's why I also have an additional Roland GK-3 pickup mounted on my Roland guitar.
Other pedals used: Ibanez Tube King pedal with gain on "0" just to warm up the sound a bit, an Electro-Harmonix Micro POG adding both an octave up and an octave down, Exar Compressor, Boss RV-5 reverb, Boss DD-6 Dig.Delay, Boss PS-5 Super Shifter and a Palmer "The Junction" DI Box.

www.ketilstrand.com
mp3 version: www.geocities.com/ketilstrand/lydklipp"

Update via Joe S. in the comments: "I have one of these. On my quest for a G-808/GR-300 setup, I stumbled across a G-505 and a GR-100 for sale. I thought at first that I might sell this setup when I found a 808/300; however, I can say now that will not be the case - as I enjoy the GR-100 a great deal!

The 300 apparently uses the hex fuzz circuit that is built into the guitar controller, but the 100 actually has provides its own hex fuzz circuit, which has a different voice - more "saturated" sounding IMO. The sustain mode is also unique to this unit (engaged using the toggle on the guitar). That, combined with the -12db/octave filtering (GR-300 has -24db/oct), inverted envelope mode, and the vibrato can really produce some interesting "synth-like" sounds, as well as that wonderful distortion tone heard in the seller's great demo video.

You can head my GR-100 setup in this track:

http://www.hillscloud.com/music/Passage-to-Infinity.mp3

I'm playing it with a G-505, and it comes in doubling the Multimoog melody. It can also be heard in the bridge section with the chorus engaged (and phasing from a frequency shifter), and you can head a bit of the vibrato kick in just before the solo section.

Sorry I don't have anything yet with it more "up-front" in the mix, or featuring a more aggressive sound - but this might give you an idea of the subtle synthetic nature it is capable of. The sounds can get much more dramatic by opening up the filters and experimenting with the envelope sensitivity.

Overall a very fun little box, and great addition to an old 24-pin setup!!"