GR-33 Guitar Synthesizer

This page is written for guitarists rather than midi/synth gurus.  If you are unfamiliar with this unit and/or are considering buying one, have a read.

The GR-33
The best way to think about the Roland GR-33 guitar synthesizer is with ambivalence.  Yes, I'm completely serious.  There are many good things that expand your capabilities musically, but there are many limitations that you will have to recognize up front... or be perpetually disappointed.

Rather than going into a lengthy product demo that you could find on the company's site, I would rather take this time to discuss the unit's shortcomings.  However, please do not perceive this section as a negative review.  I'm just presenting a balanced picture that you might not find elsewhere.

You have to understand that your playing style will have to be modified.  As you probably know already, every guitar is a little bit different.  Some require a lot of effort to get a bend to sound just right, while others are natural extensions of your ability.  Playing a guitar synth is a lot like that as well.

You're used to playing the guitar as a physical instrument.  Well, get over it.  When you are using it with the GR-33, you are fragmenting your pre-conceptions of the guitar into two distinct components: The tone generator and the trigger.

The GR-33 makes the tones from now on.  You cannot palm mute.  Harmonics sound exactly the same as any other note.  The guitar is simply a trigger.  What you can still do is to play.  You can bend strings.  You can add vibrato.  You can play at different volumes by hitting some strings harder than others.  And so on.  It takes a bit to get used to, but that's the way it works.

The pickup
Unless you have a guitar with a built-in synthesizer pickup (as is the case with many guitars from Godin and a few other manufacturers), then you will need to install Roland's GK-2A pickup.  I won't kid you, this is one of the worst things about guitar synthesizers.

Installing this pickup means adversely affecting the look of your guitar.  Honestly, it looks like your guitar has been assimilated by the Borg.  While I'm all for interesting looking instruments, odds are you will not want to install this hunk of plastic with its glowing red eye on your prized sunburst Les Paul.  Believe it or not, I got the picture from the company's own web site.  Go figure.

Further, this pickup just plain gets in the way.  You simply will not be able to use your molded hard-shell case with the pickup sitting on the guitar's face.  Nor will you be willing to use a gig bag since the pickup's control unit cost ~$200 and is made of ordinary plastic.

The GK-2A listens to each string individually through six independent pickups and sends these signals to the synth.  The job of the guitar synth is then to determine the pure tone being played on the string so that it can then trigger a synthesized tone of equivalent pitch.

The only problem is that guitar's don't make pure tones.  That's part of why they sound so good.  Each string contains a mixture of harmonics whether you play them or not (For further reading, look up what a Fourier transform does).  Sometimes the GR-33 (or, for that matter, any other guitar synth) will misinterpret the tone as one of these harmonics.  The result is a "squawk."

In addition to falsely reading notes, the unit sometimes misses them.  I'm not sure whether it just can't keep up or if this also stems from an inability to correctly interpret these signals.

One thing that I think helps matters considerably in my case is that I am playing through piezo pickups (via a Godin LGX-SA) rather than the magnetic ones in the GK-2A.  While I still get occasional squawks, these seem to be less frequent than the problems I had using the GK-2A.  I suspect part of the problem is that the pickup is supposed to be placed against the bridge.  This actually makes it harder to analyze the frequency (since this is where there is the least "sweep" of the string) and where there are the greatest harmonics (if you play heavy metal, you already know this).  By contrast, the piezo pickups "feel" the string, so they're much more accurate at telling the unit which note(s) you're hitting.

Comparison to the GR-30
I had previously owned a Roland GR-30 and had very mixed feelings about it as well, to say the least.  When I say "mixed," I mean that I loved some things about it and absolutely hated others.  Pretty quickly, the negative outweighed the positive, and I returned it after a few weeks.  Fortunately, the GR-33 was a significant improvement over the earlier model.  At least 90% of the improvements were just in updating the user interface.

For those considering a cheaper GR-30 still floating around on eBay, here's my advice: Don't.  That unit has all the problems outlined above, plus a useless interface.  It is almost impossible to edit the GR-30 or to understand even what you were doing.  By that, I don't mean that this was brain surgery, just that there was no feedback.  The unit consisted of a couple of dials and an LED display simpler than your alarm clock.

By contrast, the GR-33 has a more expansive screen that tells you what you're doing and, more importantly, what you're playing.  Whereas the 33's screen will now tell you if you're playing a bass, a banjo, or a bassoon, the 30 left you wondering, "What the hell did I save to patch A14?"  I have no idea how many embarrassing moments this resulted in at a gig, but I'm sure no one wanted to be the brunt of the joke this unit was.


Getting back to the GR-33, there are a number of capabilities it opens up.  The advantage of MIDI is that devices can be connected.  For those unfamiliar with MIDI, here are some of the possible outcomes of connecting the GR-33 to various peripherals:

Computer to GR-33
  • Edit the programs
  • Save the programs (as back-up)
  • Load new programs
GR-33 to Computer
  • Sequencing
  • Record directly (using an audio cable rather than MIDI)
GR-33 to Synthesizer (or sound modules) 
  • Access keyboard's sound bank and play it through the guitar/GR-33
Synthesizer to GR-33
  • Access guitar synth's sound bank and play it through the keyboard
Computer to Synthesizer (or sound modules) 
  • Edit the program
Synthesizer (or sound modules) to Computer
  • Sequencing

The bottom line
Ultimately, a guitar synth like the GR-33 offers you the opportunity to acess the advantages of MIDI (e.g., new tones, sequencing, etc.) while retaining (most of) your proficiency with a familiar instrument.  I'm not much of a keyboardist, but I know I can rock on a guitar.  Unfortunately, there are a few trade-offs, but something is better than nothing.

I think the price is pretty reasonable for serious musicians to give this technology a shot, but weigh the advantages against how much of an investment this will be for you.

GR-33 links Did I miss any good ones?  If so, please write me.

Copyright Alexplorer.