Roland GR-33B Bass Guitar Synthesizer and G-88 Bass

GR-33B Bass Guitar Synthesizer

Introduction to the GR-33B:

The Roland GR-33B is the bass guitar version of the GR-300. Some changes were made to meet the specific needs of bass players. Also, there is no hex fuzz circuit. The GR-33B also has two selectable envelopes, and a choice of VCF and/or VCA modulation. While the GR-300 has a -24 dB per octave filter, and the GR-100 has a -12 dB per octave filter, the GR-33B actually has both, with a switch to select -12 dB or -24 dB operation. There is no pitch sweep like on the GR-300. The GR-33B has a very cool variable LFO delay. This delay follows the envelope generator. This means you can play a note and hear the LFO quickly or slowly swell in. Playing notes rapidly means that you will not hear the vibrato effect. It is very expressive, and makes sense for the bass player that may not want constant vibrato. If you check out the Frankenstein demo, you will hear vibrato swelling in on the main line. I did not use the touch pads to activate the vibrato each time I played the phrase, but instead set a short delay so the vibrato would swell in on the longer quarter notes in the melody.

The GR-33B Synth Engine:

The GR-33B sounds very much like the GR-300. If you compare the block diagram for both synths, you will see that they are basically the same. Likewise, the synth response time for the GR-33B is very fast, like the GR-300. I did a few timing checks when recording demos for the GR-33B, and the delay was in the range of 2 - 4 milliseconds. This is the kind of speed that a digital synth could only dream of.

I would like to mention that I really wish the GR-33B provided access to the square wave output. Like the GR-300, the main output is an unusual ramp waveform. When the duet mode is engaged, you can hear a square wave and the ramp wave. The problem is the aggressiveness of the ramp wave. It is much more like a brass wave, than the buttery smooth sound of a classic Minimoog bass patch. You can filter the ramp wave to eliminate the aggressiveness, but the waveform becomes very dark with few harmonics. You can hear this sound in the VCF and VCA modulation demos below. The Frankenstein demo also shows off the aggressive sound of the GR-33B.

Finally, the response of the GR-33B system has some uneven areas compared to the GR-300, which has flawless tracking. In particular, playing the low E and low A strings can confuse the synth tracking system. The problem does not seem noticeable with the D and G string. I spent an entire weekend testing my system before concluding that the GR-33B is pushing the limits of guitar synth technology with the low notes. Mark Smart, a serious musician and guitar synth genius reported to me that his main problems with tracking came from the lowest notes. And I was able to exchange emails with Pablo Leocata, another serious GR-33B user who reported similar playability. Depending on how you play, this could be unnoticeable, or an annoying inconvenience. My theory that this issue has to due with the different quality in sound from the open strings to the fretted strings.


This is a trace of the basic waveform from a Roland GR-33B bass synthesizer. No surprises here, the waveform is basically identical to the GR-300.	The top trace is a VG-88 simulation of a GR-300, the bottom trace is the real thing. Aside from a slight harmonic bump in the VG-88, they are very similar.	This is waveform number 477 "GR-300 Saw 2" from the Roland SRX-07 Ultimate Keys Expansion card. This is an excellent sample of the GR-300.

Features of the GR-33B:

4-voice polyphony

2 oscillators per voice

VCOs are directly harmonically locked to each string, but can be tuned separately

2 Presets for Envelope Generator with Attack and Decay Control

Selectable -12 dB or -24 dB VCF with Envelope Modulation

VCA Controlled by Dynamics or Envelope Generator

Envelope Triggered Low Frequency Oscillator with Delay, for Vibrato Effects

Built-in foot switches control the VCO harmonize pitch (detuning of the VCO's)

Built-in foot switch controls the VCF mode (on, bypass, or inverted)

Pedal control input for the VCF

String Select Feature in Individually Engage/Disengage Synth Sound per String

The GR-33B can output either the guitar, the synth, or a mix of the two

Synchronized, flashing LED status indicators

All-Analog Construction

The GR-33B and G-88:

The hard-to-find Roland G-88 Bass.

The GR-33B was packaged with the G-33 or G-88 bass guitar controller. Like the G-303 and G-808, the basic design of the bass guitar is the same for the G-33 and G-88. Both the G-33 and G-88 have the exact same electronics. The G-33 has a rosewood fingerboard, and the G-88 has an ebony fingerboard. This parallels the G-303 rosewood fingerboard and the G-808 ebony fingerboard. Both guitars feature through-neck construction. And, like the G-303 and G-808 pair, the G-33 has a silver/nickel hardware and the G-88 has gold/brass hardware.

I can report that the G-88 is a really wonderful bass guitar. This is no surprise to people who remember how popular 1980’s Ibanez bass guitars were. The G-33/G-88 bass guitar seems to be a variation on the Ibanez MC-800 bass, though its basic features are found on all the Ibanez MC bass guitars. Like the high-end Ibanez basses, the G-33/G-88 has active electronics. The G-33/G-88 has two bands of active equalization, bass and treble. The electronics are powered by two 9 volt batteries or by power provided by the guitar synthesizer. There is an access door on the back of the G-33/G-88 for the battery compartment.

Body:

Ash and Walnut
Finish: Acrylic, natural
Neck: Maple and Mahogany, thru neck
Fingerboard: Select Ebony
Frets: 21
Bridge: Adjustable
Nut: Polycarbonate
Tuning Machines: Gotoh
Pickups: One single-coil
Scale: 34”
Truss Rod: Single, adjustable
Neck Width: 1 11/16 ”
Body Width: 13 ”
Body Depth: 1 3/4 ”
Overall Length: 45 1/2 ”

Details: Front of G-88


Headstock	Ash and Walnut Body	Synthesizer controls with overlay.	Bridge and tailpiece
Click on any photo to open a much larger picture in a new window.

Details: Back of G-88


Original Gotoh tuners	Beautiful through-neck construction	Back of guitar with electronics compartment	Vintage 24-pin guitar synth connector
Click on any photo to open a much larger picture in a new window.

New Video Demos of this G-88 and GR-33B:

	G-88 Direct and with GR-33B
	In this video you can hear the dry, direct output of the G-88, with no effects. At first Brad cranks up the active low eq on the bass, then adds the high band active eq for some bass slapping. Next the GR-33B is added, with various filter settings, pitch offsets, and some filter modulation with resonance. During the recording, Brad remarked what a great bass the G-88 is as a stand alone instrument. Brad Rabuchin.
	G-88 and GR-33B Filter Pedal Effects
	This video clips highlights using the GR-33B with the filter pedal, which allows the player to sweep the filter. I noticed the GR-33B has a "Mu-Tron" vintage filter sound. The GR-33B offers both -12 dB and -24 dB filter effects. Notice how well the GR-33B tracks everything Brad plays.
	BX-13 V2 Bass Synthesizer Control
	The BX-13 V2 is used here with a Roland GI-20 driving a Roland XV-5080. I also demonstrate using the optional EV-5 pedal to create volume swells with the natural bass pickup output. The Roland GI-20 has a rear panel switch for bass operation.

I would like to thank my friend Brad Rabuchin for helping me out with these demos. I was a bit weary of hearing myself play the same tired pentatonic riffs, and Brand kindly stepped in to liven things up! Also, if you notice some slight clipping in the demos, this was my fault as I was inadvertently overdiving the input to my Canopus ADVC-100 video capture unit.

GR-33B Block Diagram:

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

Front Panel Controls:


Pitch controls with LFO Rate and Delay	-12 dB or -24 dB filter.	Selectable Envelopes for VCA or VCA.

Rear Panel Connections:


Filter pedal sweep input and String Select switch input.	Guitar and Synthesizer outputs.

Recording the G-88 with the Roland SIP-301 Bass Pre-Amp:

The direct bass tones (not the synth bass sound) recorded on this page were processed with the Roland SIP-301 bass pre-amp directly into Digital Performer. I hoped this would give the final vintage touch to these recordings. The SIP-301 is a pretty cool box. It basically it combines a very aggressive compressor with a three band equalizer. In addition to three tone controls with selectable frequencies, there are high and low shelving filters. And there is also a built-in crossover for biamp applications, and two effects loops, pre and post equalizer.

Roland SIP-301 Bass Guitar Pre-amp. Click to enlarge.

Download the Roland SIP-301 Manual

GR-33B Musical Samples:


Variations on the classic Edgar Winter "Frankenstein."	"Birdland" bass line, synth panned left, bass on right.

If the patch sounds stereo, like the filter sweep at the beginning of Frankenstein, then I double tracked the part. If the part is in mono, as most of the playing is, then the layered sound comes from the dual oscillators in the GR-33B. In the Birdland demo I panned the synth left, and the bass right. Spectrasonics adds some loops in the Frankenstein track.

GR-33B Modulation Effects:


No modulation.	VCF Modulation	VCA Modulation	VCF and VCA Modulation.

In these examples I played the same phrase and added the VCF and VCA modulations to demonstrate how they effect the sound. The filter was set to the -12 dB position. Notice that VCA modulation really cuts short the sound.

GR-33B Filter Sweep Samples:


Filter sweep with maximum resonance, using -12 dB filter.	Filter sweep with maximum resonance, using -24 dB filter.	GR-300 filter sweep with maximum resonance.

These samples were recorded with the resonance control set to maximum to emphasize the sweep of the filter. Samples were recorded in Digital Performer.

Download the Roland GR-33B Manual

Origins of the Roland Bass Guitars:


Ibanez MC-800	Roland G-88	Greco GOB II Bass
It is often reported that the Roland guitars and the Ibanez IMG2010 guitar were built by the Japanese guitar builder Fuji Gen Gakki. The name "Fuji" comes from Japanese icon, Mount Fuji. "Gen" means stringed, and "Gakki" means musical instrument. Fuji Gen Gakki built a lot of guitars, for a lot of people, including Greco Guitars. Greco Guitars were sold almost exclusively in Japan. Fuji Gen Gakki also built guitars for Ibanez, Fender, Fender/Squire, Yamaha, and of course Roland. Contractors could provide their own designs to Fuji Gen Gakki, but often they would consult with the Fuji Gen Gakki engineers, and make modifications of existing designs. This explains the similar designs and features of Roland and Ibanez guitars of the same era. The 1981 Greco Catalogue shows every Roland guitar synth product in production at that time. The Roland G-808 is a modified version of the Greco GO1000. These Greco guitars are excellent, top-of-the-line instruments. In case you are wondering, it has been suggested that the "GR" at the top of every Roland guitar actually stands for Greco-Roland.

Performance and Setup Tips from Pablo Leocata :

The Roland GR-33B user Pablo Leocata was the owner of the Bass Center in Buenos Aires ,Argentina and he was kind enough to share tips for using vintage Roland Bass synthesizers. Pablo’s rig includes two G-33s, two G-77s (one of them fretless!), two GR-77Bs and one GR-33B. Pablo also uses a US-2 unit selector and a BC-13 buss converter to control the Roland V-Bass

Pablo feels that some of the negative remarks he has seen from people about the Roland bass synths come from users that do not really understand what they are playing.Bass & guitar synthesizers have a whole new language to learn, not only music, but also a new technique and some knowledge of MIDI, synthesis & electronics. Pablo regards these vintage instruments as undervalued. As with most guitar synthesizers the Roland basses "require patience and dedication to work properly." A guitar/bass controller/synth package is not a "plug & play" proposition. They are sophisticated technology pushed to the limit. Its creative possibilities are endless but only for those who are ready to accept a whole new way of thinking about their instrument. Pablo continues "One of the secrets I find are the strings. You can not use standard string sets because they have big differences in tension, sometimes more than 2 or 3 kgs (4 to 7 pounds) between strings. This difference in tension affects the attack, and it can not be controlled by adjusting the gain trimpots inside the guitar. I recommend custom or balanced string sets.

Pablo also reports having the same problems I reported with open strings. "In my case, I have a problem only with the 4th string. I have troubles with the E string, but if I detune the string to D and fret an E on the second fret, the sound is perfect. I suppose this is a problem of the G-33, and perhaps this is why Roland added the graphite bar to the G-707 and G-77. Also, the position of the quad pickup seems too far from the bridge, and it picks up a lot of extra harmonics."

Pablo also reports he is able to use the G-33 and G-88 with a GR-77B, but it is necessary to set the trigger level of every patch to zero. According to Pablo, the G-33 and G-88 have more gain, and the G-77 does not generate sufficient gain to drive the GR-33B. Pablo continues, "On the GR-77B the secret is to set the oscillators range to the same octave on the bass, and take special care about the envelope settings. If you have clean technique, proper strings and setup, and a correctly calibrated system, it is possible to get very good results."

Pablo included references to these examples of string tension differences on standard and custom sets of bass guitar strings:

Standard Set String Tension:

D ’addario EXL220 Super Light Bass Strings.

D ’addario EXL170 Regular Light Bass Strings.

Custom String Set Tension:

Ken Smith Custom Balanced Round Wounds

Well said Pablo, and I think that is pretty much true for all guitar synthesizer rigs!

If other Roland synth uses have tips they would like to share, please feel free to send me an email, and thanks again to Pablo Leocata for sharing his tips and photos for this website.