Roland GR-700 Analog Guitar Synthesizer

Roland GR-700 Analog Guitar Synthesizer


Introduction to the GR-700:

    The GR-700 is classic Roland analog synthesizer technology. Released in late 1984, the GR-700 is the pinnacle of early Roland guitar synthesizer design. The distinctive and futuristic GR-700 features both a digital CPU for guitar tracking and a warm, fat hybrid digital/analog synthesizer engine for lush sounds. The GR-700 has a MIDI out port for controlling other MIDI modules, but the MIDI output is erratic and unreliable. In addition, no pitch bend information is sent via MIDI either.

    Like the current generation of Roland guitar synths, the GR-700 controls the internal synth engine directly for faster response. But, make no mistake about it, the GR-700 is not a GR-300. Of all the products Roland has ever made, the GR-700 has the trickiest and most erratic tracking. The GR-700 is certainly better than equivalent products made by other manufactures at the time, but it is inferior to the GR-100, GR-300, GM-70 or the Ibanez MC-1.

    For players who were used to the accuracy and speedy response of the GR-300, the GR-700 seemed like a real step backwards. Still, the GR-700 did introduce a new level of programability for guitar synthesizers. And when you consider the design and engineering costs of the Roland G-707 and GR-700, it is clear that Roland made a major commitment to guitar synthesizers.

    The GR-700 Synth Engine:

    The GR-700 has six, independent, analog synth voices, two oscillators on each voice. Roland digitally clocked these oscillators and called them "DCOs", as a response to the fact that the earlier Roland oscillator’s pitch had a tendency to drift in performance. The DCOs on the GR-700 generate classic analog waveforms: sawtooth wave, square wave, and pulse width modulated wave, as well a noise for special effects. The oscillators on the GR-700 can also be synced with cross modulation for hard, biting analog sounds or with ring modulation for metallic sounds. The GR-700 has a sweet Low Pass Filter with Resonance on each voice, with an additional High Pass Filter. And of course there are complete LFO and Envelope controls. To top it all off, the GR-700 adds a classic Roland analog Chorus circuit! If you like that expansive Roland Chorus found on early 80s products, you will love the Chorus on the GR-700.

    The synth engine in the GR-700 is the same synth engine found in the Roland MKS-30 and Jupiter JX-3P. And, like these synths, the Roland GR-700 can use the PG-200 as a programming tool. See below for more information on the MKS-30 as an alternative to the MKS-30.

    What Guitars can use the GR-700?

    The GR-700 was originally designed to work specifically with the G-707 guitar, however, in my opinion, the best controller for the GR-700 is the excellent Ibanez X-ING IMG2010 guitar. The IMG2010 incorporates many of the features of the G-707 guitar, such as graphite reinforcement for pitch stability, without many of the G-707 "quirks". Naturally, the GR-700 will work with any Roland GR-series guitar, like the G-202, G-303, G-505, G-808 or any guitar with a GK-1 pickup attached, or LPK-1 or STK-1 hardware installed.

    Who uses the GR-700?

    The GR-700 was played and recorded by such prominent guitarists as Al Dimeola, Robert Fripp, Jimmy Page and Andy Summers. The GR-700 was the top-of-the-line guitar synthesizer system in the mid-eighties. Retail price on a GR-700 was almost two-thousand dollars. More recently, Amir Derakh has used the Roland GR-700 extensively on several records.

Features of the GR-700:
  • 6 voice, Dual Oscillator Synth Engine Based on the Roland JX-3P/MKS-30
  • 3 - Selectable Octave Settings for Each Oscillator, 2’, 4’ and 8’
  • Choice of Square, Sawtooth or Pulse Waveform, plus Noise for Oscillator 2
  • Cross Modulation Between Oscillators
  • Frequency Modulation with Envelope and/or Modulation
  • VCF Low-Pass Filter with LFO, Envelope and Pitch Modulation
  • Variable High-Pass Filter
  • Four Stage Envelope Generator
  • Low Frequency Oscillator for Vibrato Effects
  • Selectable Dynamic Control Over Pitch, Filter and Amplifier per String
  • Selectable Pitch Bend, Hold and Voice On/Off per String
  • Lush Analog Chorus Mode
  • Stereo Output: XLR or .25" jacks
  • Pedal control input for the VCF
  • The GR-700 can output either the guitar, the synth, or a mix of the two
  • Programming Via Foot switches or with optional PG-200 Programmer
  • 64 - Voice Internal Memory, Expandable to 128 Voices with M-16C Memory Cartridge
Manuals and Documentation:

There were two versions of the GR-700 manual. This is the original manual.
Roland slapped a new cover on the manual to make it consistent with newer products.
Double-sided, one page Roland G-707 setup instruction sheet.
The Sample Sound Unit Memory lists the original factory patches.
Adhesive backed EDIT MAP listing all the edit functions.


The Rare Roland GR-700 Case AB-700:

Roland made a few custom cases for the Roland GR-700. These cases are well built, though not quite up to ATA standards. The case included two pockets perfect for holding your manuals and accessories.


M-16C Memory Cartridge:

These handy-dandy little cartridges double the memory of many Roland devices. Used with a Roland GR-700, patch memory goes from 64 to 128 patches. With a JX8P you add 32 more patches, and it can be used for synth patches on the JX-10 or for sequence memory!


PG-200 Programmer:

Roland also made the PG-200 programmer to help program the GR-700, JX-3P and MKS-30. Like other Roland programmers, the base is covered with a magnetic material to allow it to securely attach to the top of the GR-700 or the JX-3P synthesizer.


GR-700 Block Diagram:

Click on the above diagram to open a much larger picture in a new window.


    Software Version:

    I have been able to document five different versions of software for the GR-700. The most common version in my experience is version 4. The GR-700 service notes explain the differences for versions 1, 2, 3 and 4. I have seen a few GR-700s with version 5 software. What version software does your synth have? This is easy to check! Power up the GR-700 while holding down the STRING SELECT NO. 4 button. The display will show the software version, 1-4 means version 4. 1-2 indicates version 2 software. Incidentally, the patch corresponding to the software version will selecting when doing this procedure.

    Here are the differences between the software versions:

    • Version 1: Initial software release, with the original GR-700 patches.

    • Version 2: Version 2 allows the changing of the Chromatic circuit equal temperament pitch. In Version 1, if you are in chromatic mode, and play an "A" you will hear a note pitched at 442Hz. While A=440Hz for most Americans, some European orchestras use A=442Hz, and A=445Hz in Germany, Austria and China. With version 2 software, you can press 4 - 8 while in edit mode and adjust the chromatic pitch of "A" from 438 to 446Hz using the EDIT (resonance) knob.

    • Version 3: The GR-700 can fail to maintain sustain level is the EDIT (resonance) knob is turned to maximum when the SUSTAIN LEVEL is being edited. The software address this problem.

    • Version 4: In earlier versions, the frequency range which is covered and defined as the note "B" is narrower when compared with that of other notes. As a result, a note in the lower "B" range would be recognized as "A#" Version 4 fixes this problem.

    • Version 5: No revision notes available.
Power up the GR-700 while holding down the e STRING SELECT NO. 4 button.

The display will show the software version, 1-4 means version 4.
Initializing Patches:

    It is possible to reinitialize the first four banks of patches for the GR-700, banks 1 though 4. There is no way to recover patches in banks 5 through 8 if they have been lost.

    To reinitialize patches in banks 1 - 4, turn on the power switch while pressing down the WRITE (copy) button. Be sure to have the memory protect turned off.
    		To reinitialize patches in banks 1 - 4, turn on the power switch while pressing down the WRITE (copy) button.

    Be sure to have the memory protect turned off.


Behringer FCV-100 Control Voltage Pedal used with the Roland GR-300 and GR-700 Vintage Guitar Synthesizer:

Behringer FCV-100 with Modified Cable: GR-300 and GR-700 Filter Control
The Behringer FCV-100 makes a great pedal to control Filter Cutoff with both the GR-300 and GR-700. This clip shows the pedal in action. The pedal can also be used to control Pitch with the Roland GR-700.


    The Behringer FCV-100 is a well-built pedal that can function as a dual, stereo volume pedal, or as a control voltage pedal with a 50K pot. However, the FCV-100 cannot be used directly with the GR-300 or GR-700. Since the FCV-100 has an internal PC board, the easiest way to adapt the pedal for the GR-300 or GR-700 is to modify a TRS tip-ring-sleeve cable.

    This is how I modified a cable for the FCV-100: The end used to plug into the FCV-100 is left unchanged. The end used to plug into the synthesizer (GR-300 or GR-700) is changed in the following manner: The sleeve (ground) connection is cut, and the wire attached to the ring is moved to the sleeve (ground). By making these changes, you will get a bright filter sound when the pedal is fully pressed down.


Click here to see a large photo of the modified cable for the FCV-100.

Analog Calibration:

    Since the GR-700 is an analog unit, it requires calibration from time to time. The many analog components in the GR-700 give it a fat, unique sound. However, with time these functions can drift, and many GR-700s may not sound as good as they originally did from the factory. With some basic test components, such as a multi-meter and oscilloscope, it is fairly easy to re-calibrate the GR-700 to factory specification. The details are outlined in the service manual, with a download link below:

    • Main board Voltage reference set to 4.7 plus/minus 0.01V
    • DCO-1 reference tuning set
    • DCO-2 and DCO-1 tuning set
    • D/A Offset for maximum output before clipping
    • Level adjustment for each individual voice
    • VCA DC Balance set for each voice
    • VCF filter level adjustment for each voice
    • Final chorus bias adjusted for proper stereo imaging and fattest chorus tone


GR-700 Calibration Videos:





Front Panel:


Click on any image for larger view.
Rear Panel:


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Roland GR-700 Short Audio Samples:

Demo 1-2 1-6 2-1
Demo GR-700 Sounds
Factory Patch 1-2
Factory Patch 1-6
Factory Patch 2-1
2-5 2-6 3-2 5-8
Factory Patch 2-5
Factory Patch 2-6
Factory Patch 3-2
Factory Patch 5-8
64 Sounds Low-resolution (8-bit) demo of 64 GR-700 Sounds Playing Open D String. I created this demo with patch 65, called "GR-700-AUDITION.nki". This single patch starts with low A on a 88-key MIDI controller, and assigns each GR-700 patch to a single key, going up the keyboard. You can load this patch as a quick way to audition all 64 sounds.


Video Samples of the GR-700:

RC-1324 with Roland GR-700 and Brian Moore i2.13 Guitar
A Brian Moore i2.13 guitar is used with the RC-1324 to drive a GR-700. The Filter knob is used to edit the cutoff frequency, and the Resonance knob is used to edit the pitch range of DCO 1.
XJ-S with Roland GR-700 and PG-200
This video demonstrates the XJ-S with a Roland GR-700 being programmed with the PG-200. All the editing features of the PG-200 are used in this video.
Introduction to the GR-700
Analogger created some great vintage Roland synth videos on YouTube. Click on the picture to see a QuickTime clip, created by Analogger, or go to YouTube to see the original.

Problem Solved! The 80017a Chip:


    If you are familiar with the eighties Roland synthesizers, then you have likely heard about the dreaded 80017a VCF/VCA chip failure issue. Many synthesizers built by Roland in this period used the 80017a chip: the Juno 106, MKS-30, HS-60 and of course the GR-700. The 80017a is basically a voltage-controlled filter and a voltage-controller amplifier on a single, customized chip made for Roland. The actual components in the 80017a were found as individual elements in the earlier Juno 60 synthesizer: an IR3109 and two BA662 chips. The IR3109 was also used as the heart of the excellent -24 dB low-pass filter in the Roland GR-300.

    Why exactly Roland chose to consolidate those three chips (and some surface mounted resistors and capacitors) onto a single ceramic chip dipped in plastic remains a mystery. Arp did something similar with its 4034 filter module, perhaps to (unsuccessfully) dodge a lawsuit from Moog. In any case, early in the process there were failures with the chips, and Roland issued a service bulletin and replaced lots of chips. Then, as the chips aged, problems started to show up with again. Third party suppliers started making clones of the original chips using modern equivalents. And I sold quite a few working chips on ebay after gutting GR-700s for parts. I extensively tested these chips, and no one had a subsequent failure from the chips I pulled. But this bothered me: would it be possible to modify a GR-700 in some way that would guarantee against a future 80017a chip failure?

    As it turns out, the answer is to remove the problematic resin coating around the components. And this was not my idea, someone sent me a link to a YouTube clip showing how to get the job done. I happened to be working on a GR-700 that needed five (!) 80017a chips. I had five failed chips on hand, and used the Acetone procedure to remove the resin. Each chip was then individually tested in a special socket, running continuously for 12 hours with no failure. As each chip passed the test, I labeled it and replaced it in the GR-700.

    The result is flawless operation. I do not know why the resin causes problems, but I am guessing that with aging the resin builds up electronic capacitance, causing the chip to fail once the temperature in the synthesizer warms up. This is the best possible solution to the 80017a problem. You keep the original chips that Roland designed, maintaining the sound of the instrument, and you protect against future failures as well.
Failed 80017a chip from lot number 42B, with resin in place.
Resin shell removed from the chip by soaking in Acetone.
Tested and relabeled chip, ready for installation in the GR-700.
The custom Roland IR3109 chip shown in the GR-300. This chip is part of the 80017a assembly.
Click on any image to enlarge in new window.
1984 Roland GR Brochure:


Click on any image for larger view.
Magazine Advertising:


Click on image for larger view.


Documentation and Downloads:

Download the Roland GR-700 Manual

Download the Roland GR-700 Service Manual

Download the Roland Original GR-700 Version One Factory Patch List


GR-700 Pitch-to-MIDI Speed Test:

    I did some testing one morning, to compare the speed of various guitar synthesizers. I played open strings, fretted at the fifth fret, and the twelfth fret. I recorded the direct output from the 1/4” jack on the guitar and the output from the synthesizers. MIDI only converters like the GM-70 or GI-20 were used to drive a Yamaha CS6R. The exception was the MKS-30 which was used with the GI-20 to create a GR-700. I felt using MIDI modules was more of a real world test.

    The GR-700 did OK in the speed tests, faster than the MIDI only MC1 and GM-70. Here are the average results:

    GM-70: 40.39 milliseconds.

    MC-1: 33.62 milliseconds.

    GR-700: 29.87 milliseconds.

    MKS-30 with GI-20 (GR-700) : 27.24 milliseconds.

    Korg Z3: 20.15 milliseconds.

    GI-10: 21.99 milliseconds.

    GI-20: 19.77 milliseconds.

    VG-88 (Polyphonic Pitch Transpose): 7.34 milliseconds.

    VG-88 (GR-300 Simulator): 5.38 milliseconds.

    GR-300: 3.32 milliseconds.

    I would be a little more excited about the GR-700 if it was not for the fact the the synth easily produces the same kind of tracking errors found on earlier Roland guitar synths like the SPV-355. If you really love the sound of the GR-700, my suggestion is to use a MKS-30 with a modern Pitch-to-MIDI converter for similar performance and more accurate tracking.

    The GR-700 is an unusual guitar synth in that the same sound engine is available as a rack-mount MKS-30 or the JX-3P. Of course, there is no equivalent to the GR-300 or GR-100!

MKS-30 Planet-S Module: Same Dynamic Synth Sound as the Roland GR-700 but FASTER!

MKS-30 with Rack Ears attached.


    Many vintage guitar synth players love the sound of the Roland GR-700, and continue to play this unique guitar synthesizer, despite the poor tracking. Certainly, the GR-700 looks cool, sounds great, but it is very difficult to play consistently. However, as an alternative, you can get the great sound of the GR-700 by using the MKS-30 with a Roland GI-20 modern pitch-to-MIDI converter.

    The MKS-30 when used with a GI-20 actually responds on average 2 milliseconds faster than the original GR-700, and with an accuracy never possible with 1980’s technology. On the higher strings, the GI-20/MKS-30 combination can even be 15 milliseconds faster.

    Furthermore, the GR-700 does not have a MIDI input, so it cannot be used as a synth module like the MKS-30. GR-700 users will notice that the MKS-30 does not have the exact same string functions as the GR-700, like string on and off select (mute) and pitch bend select. However, many of these features can be re-created using the GI-20, which allows individual strings to be muted, and also allows other features like individual pitch transposition of strings, making it easy to create "drop-D" tunings and the like.

    The MKS-30 also has the same slot for the M-16C memory cartridge. Like the GR-700, the M-16C can be used to double the memory of the MKS-30 from 64 to 128 programs. Because of slight programming differences in peripheral parts of the MKS-30, GR-700 and JX-3P, the cartridge needs to be formatted for each synth individually.

    Modern guitar synth players can plug directly into the GI-20, and vintage guitar synth players can use a Roland BC-13, SBC+, DC-13 or BX-13 to convert 24-pin signals into 13-pin signals compatible with the GI-20. Naturally, it would be possible to use a GM-70 with the MKS-30 as well. This rig would have more accurate tracking, but the response time would be slower the GR-700. I expect a Roland GI-10 would also yield good results, but it lacks the programming options of the GI-20.


The GI-20 turns the MKS-30 into a Roland GR-700 Guitar Synthesizer.
Add a BC-13, BX-13, DC-13, or SBC+ to use vintage guitar synths.
The GR-700 manual (left) has the same programming section as the MKS-30 (right).
MKS-30 Front Panel Details:

Global tune, volume and brilliance controls.
Parameter editing and LED display.
M-16C memory cartridge slot.
MKS-30 Rear Panel Connections:

MIDI input and thru.
Stereo and mono outputs.
High, medium and low level.
Power connection.
MKS-30 Audio Samples:

Repeated bass line with patch changes. Spectrasonics Stylus RMX adds a loop occasionally, and a second track of MKS-30 overdubbed some random S/H leads. Delay and reverb adding in Digital Performer on leads effects, but bass is direct from MKS-30.
Classic Handel’s Bourree playing with one MKS-30 track. Random program changes audition poly pads, sound effects, clangorous tones and analog effects. Recorded dry direct to Digital Performer with no effects or processing. Stereo chorus effect from MKS-30.
The MKS-30 was recorded four times, with a variety of patches. There is a mellow repetitive motif, high expressive lead, filter sweeps and effects. Digital Performer was used to add varying amounts of delay to the pads and lead tracks.
I recorded these audio samples were recorded with the Roland MKS-30. There are very few demos on the web of this amazing synthesizer. The samples were recorded into Digital Performer, with delay and reverb added on the first and third track during mixdown. The Handel track was recorded dry. Each demo is about 700K in size.


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