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.

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

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.

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, available from Roland:

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

Rear Panel Connections:


The 24-pin Roland connector work with the G-202, G-303, G-505, G-707, G-808 or guitars with a GK-1, or LPK-1	This is a professional unit with both 1/4“ and XLR outputs, plus unbalanced stereo and mono outputs and foot pedal inputs

GR-700 Short Audio Samples:


Classic S/H filter modulation	Lead Played with hammer-ons	Lush analog filter sweep	Flute tracking dynamics/glissando	Joe Zawinul-type analog bass

These audio samples were recorded with a Roland GR-700 and Ibanez IMG-2010. The samples were recorded into Digital Performer, with delay and reverb added during mixdown. These are not the original factory patches.

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.

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.

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!

Important Note on Buying a GR-700 or MKS-30:

If you are considering buying one of these synths, I would make sure that all the functions work correctly. I think 2 out of 3 GR-700s that I bought off ebay arrived with something broken. And I think most of the sellers were unaware anything was wrong. This is a problem, because of the size and shipping costs of a GR-700, you can easily regret ever bidding on one. Most sellers seem to power the unit up, listen for a few sounds, then list the unit on ebay. Here are some questions to ask the ebay seller before you bid!

Do all the the foot switches operate properly?

Can a patch be edited using the guitar controls with the foot switches?

Can a patch be edited using a PG-200 programmer?

Do the top panel membrane switches work?

Can you edit and save a patch, power the unit off, and check the edited patch again after power up?

Does the unit still work properly after running for half an hour? This is to see if problems occur after the unit warms up.

Finally, the voice board for the GR-700, MKS-30 and Juno-106 uses a custom Roland chip: AIQH80017A or AIQH800170, frequently referred to simply as 80017a. This chip combines VCF and VCA functions. This is a very, very rare chip, and there was a bad production run that ruined many synthesizers.

You want to be absolutely sure that all the voices work correctly with no filter or VCA problems. Filter problems would be things like one voice that is bright, or not responding to filter commands. VCA problems might be one voice that does not make any sound or a voice will not turn off. On a rare occasions you can find these chips selling for $65 to $115, but this is a very hard part to find. To fix a unit with this problem could well cost $300.

The Roland GR-700 schematic showing the rare AIQH80017A VCF/VCA chip.


Interior GR-700. Voice board is on the bottom, and the VCF/VCA is on the far left.	Interior MKS-30. The MKS-30 pc board is almost identical to the GR-700, with a few more chips.	Close-up of the 80017a. Notice the nearby trimmers for Gain, DC Balance, Resonance and Cutoff.

Download Roland GR-700/MKS-30 Service Notes on 80017a VCF/VCA chip.

Download the Roland GR-700 Manual