Custom Vintage 1977 Roland GS-500 Synthesizer Controller Guitar with GR-500 Synthesizer ( GS500 / GR500 ).

The synthesizer is in "Studio" condition. I recently had both the GS-500 guitar and GR-500 Synthesizer completely checked, cleaned, and professionally set up by a Luthier / Vintage Synthesizer Repair Technician. All electrical connections and pots were cleaned, and both the guitar and synthesizer are 100% completely functional and in great working condition.

All sections of the synth controller are working perfectly as well. All sliders are tight and smooth. None are loose or wobbly. 

The Luthier also performed a complete set-up and adjustment on the guitar, and a set string height and intonation, bridge height, and pickups height were set to factory guidelines. Also, I had a new set of 10-gauge strings on it at that time as well.

The rare-earth magnet "Infinate Sustain" system is in perfect working order as well.

The "Infinate Sustain" system is litterally that! You can hit one note or one chord, and it will litterally keep on playing, almost like an organ when you have an organ key pressed.

No detectable wear on frets or fingerboard.

Neck is straight with no cracks or repairs.

Binding is ivory off-white color from aging

Only a few minor nicks in the finish around the back edges of the body, and on the back of the guitar. I tried to capture all of these these on the photos, but some are so slight that they dont show up.  

The Guitar's metal tailpiece finish is still highly chrome plated. 

The guitar case is also in very good condition. 

Shipping price includes insurance. 

Roland GS-500 Guitar (Synthesizer Controller) Specs:

Features and Specifications:

·       Body: Mahogany

·       Finish: Acrylic sunburst

·       Neck: Set maple neck

·       Fingerboard: Rosewood

·       Frets: 22

·       Bridge: Adjustable, Roland

·       Nut: Polycarbonate

·       Tuning machines: Gotoh

·       Pickups: Roland U-4000L Humbucker

·       Scale:24 3/4"

·       Truss Rod: Single, Adjustable

·       Neck Width: 1 11/16"

·       Body Width: 13 1/4"

·       Body Depth: 2"

·       Overall Length: 40"

·       Weight: 11 lbs 3 oz

Roland GR-500 Paraphonic Guitar Synthesizer Specifications: 

Guitar Section: Equalizer ON/OFF, Equalizer Frequency 

Polyensemble Section: Voicing volume, wood, soft reed, brass, strings. Envelope generator: attack, decay, and sustain 

Bass Section: Voicing volume, percussion, soft, hard, decay (long/short), string selective switch 1-6/4,5,6/5,6, Envelope generator: attack, decay, and sustain 

Solo Melody Section: Pulse width modulation (LFO/Manual/Env), mixer (square 16' 8', saw 8', polyensemble) VCF frequency, resonance, LFO frequency, Envelope generator: attack, decay, and sustain. 

Modulation: envelope, LFO, pitch follower, pitch follower or pedal control. VCA: initial gain, envelope, touch sense (2/1/off) 

Ext Synth Section: transpose, portamento time Dimensions: 603 (W) x 154 (H) x 309 (D) mm 

Power Requirements: 19 watts Response Time: 

Polyensemble: 1.14 ms, Bass 3.89 ms, Solo Synth 3.65 ms

The Roland GS-500 is the dedicated guitar controller for the Roland GR-500 analog guitar synthesizer. Even with substantial parts of its body cut away for the installation of support electronics, the GS-500 weighs in at more than 11 pounds. The GS-500 has been described as having a honey burst finish, and it is a uniquely beautiful instrument.

The GS-500 marked the beginning of the partnership of the Roland Corporation with Fujigen, the Japanese builders of Ibanez, Greco, and ultimately Fender guitars in the land of the rising sun. Products built by Fujigen for the vintage Roland synthesizers would take the name of "Fuji Roland," a marking found on both guitars and synthesizers. The  website still features a picture of the GS-500, along with the claim of building the world's first guitar synthesizer.

The neck is around 42 - 43 mm, with a pleasing modern shape. The neck is somewhat between the slimmer G-303/808 guitars, and the chunkier G-505 guitar.

The Roland GR/GS-500 paraphonic guitar synthesizer system was introduced in 1977, and it laid the foundation for the very successful Roland vintage 24-pin guitar synthesizers, like the  and , that would follow a few years later.

The GR/GS-500 uses the same 24-pin cable as the later synths, and many of the control voltages, string outputs, etc. are the same across all the synths, . The different systems are not 100% compatible, but can be engineered to work together with a few modifications.

The GR-500 has five sections: Guitar, Polyensemble, Bass, Solo Melody, and External synth. The GR-500 was ambitious in its scope. The Solo Melody section tackled nuanced pitch-to-voltage analog synthesis, with ramp and pulse waveforms and various means of filter modulation. The Bass section similarly offered different bass voicings. The Polyensemble is a pseudo-synthesizer section, using individual waveshaping of each string output to achieve a synthesizer sound without the complexities of pitch-to-voltage synthesis. Even the guitar, the GS-500, had an equalizer switch for different guitar tonalities, and a clever infinite sustain system.

This approach of incorporating different sound elements into one large system was not uncommon in the 1970s. At the same time the GR-500 Paraphonic Guitar Synthesizer was released, Roland was also making the RS-505, Paraphonic String Synthesizer, which combined strings, polysynth, and a bass section.The term "paraphonic" was invented by Roland, as a marketing shorthand for "parallel" plus "phonic."

The GR-500 has a useful output matrix. There are three separate outputs, plus one mix/combined output. Each section can be assigned to any one of these outputs. In addition, there is an external synthesizer input, so an external expansion synth can be combined with the internal sounds.

The first "synthesis" section of the GR-500 is the Polyensemble section. After some initial high-pass and low-pass filtering, each string is processed by a Roland "trigger pulse generator" chip. This is a custom chip, made for Roland by Mitsubishi, part #140-017. This is one of two custom Roland chips in the GR-500, with no detailed documentation regarding what exactly Roland put inside these chips. The tradition of the "mystery chip" continued with the  in the GR-100 and GR-300, and the  in the GR-700.

The output from these "trigger pulse generator" chips goes to both the synthesizer section, and to the Polyensemble envelope generator, where each string passes through its own envelope generator before going through a chopper gate (similar to the GR-300), then to the filter/voicing section. The GR-500 has three identical envelope generators in different sections, with attack, decay, and sustain controls. It is my experience that once a signal falls below the input gate threshold, the envelope generator closes abruptly.

The four outputs of the Polyensemble, "F", "L", "M" and "H" are filtered/equalized outputs of the same source. The Polyensemble can be played directly, or can be processed through the low-pass filter in the Solo Melody section.

The Bass section represents the first real pitch-to-voltage conversion in the GR-500. The magic of the bass synthesizer section happens in the other proprietary, custom Roland chip, part #140-016, the "fundamental generator" chip. Like the trigger pulse generator chip, the contents of this chip remain a hidden Roland mystery. The output of the "fundamental generator" chip is a square wave, used to drive the analog synthesis in the Bass section.

A string select switch allows the player to choose from having bass on all six strings, strings 4, 5 and 6, or just strings 5 and 6. The is also a dedicated touch response switch. Like the Polyensemble section, there are different bass voices: "percussion" (long and short), "soft" and "hard." And again, like the Polyensemble section, these different voices represent the same output processed through different filters. The "percussion" setting calls to mind the percussion sound of the bass section in an aging Hammond organ. The "soft" sound calls to mind an electric bass played with fingers, and the "hard" sound is reminiscent of an electric bass played with a pick. In my studio, the bass section was impressive in its thunderous, room-shaking quality.

The Solo Melody is very much an expanded version of the Bass section. The Solo Melody section uses the same proprietary, custom Roland chip, part #140-016, the "fundamental generator" chip to convert the guitar output into a square wave used to drive the analog synthesis engine. But the Solo Melody section offers the choice of a 16' or 8' pulse wave, or a 8' reverse-ramp wave. There is also a pulse width control, and the width can either be set manually, or controlled by the envelope generator, or a triangle wave low-frequency oscillator.

The Solo Melody section has a great sounding 24 dB per octave low-pass filter with resonance. The filter cutoff can also be controller by the LFO, envelope generator, manual control, or external foot pedal. In my tests, I was able to use a Roland EV-5 pedal to get very musical sweeps from the filter. The low-pass filter can also be used to process external sounds, and to process the output of the Polyensemble section.