Product Guides

GR-55 Guitar Synthesis

Paul White, editor-in-chief of the esteemed Sound on Sound magazine looks at some practical applications of guitar synthesis (hint: it’s not about playing drums on your guitar)

Contributed by Roland UK Team

The GR-55 combines two of my favourite Roland guitar technologies in a pedal format specifically designed not to intimidate the musician and I got plenty of time to play with one when I reviewed it for Sound On Sound. One is the fast-tracking, sample-based sound synthesizer section, the other is COSM guitar/amp/effects modelling.

Critics of ‘guitar synths’ often cite the need for an additional hex pickup, or the use of a guitar already fitted with one (such as the new GC-1 GK -Ready Fender Stratocaster®) as being an unwelcome inconvenience, but in reality neither of these highly sophisticated processes would be possible without it. If you want to fire sampled synth sounds from a guitar, the electronics need to be able to track the pitch of each string quickly and reliably, and the only way to achieve this is to send it a separate signal from each string. When it comes to COSM modelling the reason may be slightly less obvious as there are competing products that emulate different amplifiers and effects using a standard guitar with a single output, but with Roland’s COSM modelling, the process extends to modelling the guitar itself in addition to amps, effects, speakers and so on.

Once again separate string signals are needed to accurately model the effect of the pickup position on the guitar, especially if it is set at angle, as a Strat bridge pickup is. Alternate tunings and 12-string emulations also need separate string signals as different amounts of pitch shift have to be applied to each string.

Fortunately, the slim GK pickup system is easy to fix to most guitars providing there’s space close to the bridge. Fitting to Strats and similar guitars is easy — in fact few guitars pose real problems though I have to concede that a Telecaster with a traditional ‘ashtray’ bridge makes a less than ideal candidate. Then there are Roland compatible guitars from a number of top name guitar builders as well as the Fender® models mentioned, the latest being the GC-1 GK-Ready Strat®.

For my own studio and live work, I have a Roland GR-33 synthesizer and a VG-99 COSM guitar processor, and though each offers more features in its own specialised area than the GR-55, the advantages of combining both technologies in an easy-to-manage package are obvious, not least being simplicity of setup. You also get a pedal with the GR-55 that can be assigned to different functions for each patch, controlling such things as volume, wah, modulation effects and so on. One of the limitations of the guitar as opposed to a keyboard is that the notes can’t sustain indefinitely, but it is possible to use the foot control to ‘hold’ the sample-based synth sounds so you can create a sustaining synth pad and then play guitar over the top. When it comes to time to change chord, you release the switch, play a new chord and then hit hold again. There are also several hold modes that range from holding all the strings to just holding the ones that are playing so that you can continue playing melodies on the remaining strings after pressing the switch. If you want to play a Pink Floyd epic on your own, this is the box for you.

You can get a GR-55 with or without a GK pickup where the supplied pickup mounting parts allow for permanent fixing using screws or a less radical option using adhesive pads, which means you don’t need to modify your valuable guitar. The control box that also houses the cable connector can be fixed under the body strap pin so again, no mods are needed. A single 13-pin cable connects the guitar to the GR-55 so there’s no need for a separate guitar cable — you can pick off the regular guitar signal round the back of the GR-55 and feed it to your amp in the usual way.

Before looking at applications, I’ll take a quick look at the key features of GR-55, which is based around two separate synthesizer sound engines that can each access the same 910 voices covering both common instrument sounds and “obviously synthy” sounds. From strings to organs, to ethnic to pianos — it’s all there. The amount of editing you can do to these sounds is intentionally limited to make the thing easy to drive but there’s so much choice on offer that this really isn’t much of a restriction. In addition to these two synth sections, you get a full-on COSM modelling section that can be used at the same time. Here you’ll find guitar modelling, amp modelling, speaker modelling, more effects than you can shake a whole bunch of sticks at, plus a few rather more synth-like sounds that are based on the guitar sound from the separate strings processed via Rolands HRM harmonic restructuring process. I’m a big fan of these HRM sounds; as they are derived directly from the guitar string output rather than from triggered samples, they respond in a very tactile way to your playing and can be layered with a conventional guitar sound to create something very big and rich sounding. On top of all this you also get a simple looper allowing loops of up to 20 seconds to be stored and replayed. And for instant gratification, there’s a huge library of preset patches to take you on a whistle stop tour of the GR-55’s capabilities.

As you’d expect, you can save your own settings or patches using any permutation of the two synth sounds and the COSM sound. And if the simple editing system seems like too much trouble, there’s also an extra easy edit option called EZ Edit where you can simply control the amount of effect or dial in a brighter or warmer sound.

I’d like to introduce a practical tip at this point: Synth sounds don’t always sound their best when played through a regular guitar amp as guitar amps are specifically designed to colour the sound in a certain way. Fortunately the GR-55 gives you the option of routing the synth sounds to a separate amplifier, which could be a direct feed to the PA, a keyboard combo or even a small acoustic guitar combo such as one of the Roland AC range. For my own live work I tend to send synth sounds directly to the PA (which means I can keep the sounds in stereo), though for smaller pub gigs I’ll use an acoustic guitar combo and make do with mono synths. A keyboard combo would be a safer bet if you like exploring those deep bass synth sounds though.

Another very neat feature for live work is the ability to plug-in a USB memory stick containing backing tracks and have them played back via the GR-55. That’s not something I’ve needed myself but I can appreciate how useful it would be to those striving for a big band sound using only one or two performers. Similarly, the MIDI Out doubles as a V-link port allowing the remote control of video devices; again not a feature I’d use but some performers will welcome it as a way to add an extra dimension to their shows.
The question often arises as to whether the GR-55 can be used with separate MIDI synths, sound modules or instrument plug-ins. Simply put, the answer is yes as the GR-55 is fitted with MIDI In and Out sockets, and in the studio this is incredibly useful as you can use your standard guitar skills to play software synths and other hardware synths as well as the GR-55’s own internal sounds. Unless your playing is very clean though, you may find some stray, low volume MIDI notes appearing in your recording but it is a simple matter to use the piano roll editor in your DAW to identify and remove these if they’re audible.

I think it is also fair to mention that the internal sounds trigger more ‘elegantly’ than external synths because inside the box, Roland’s engineers are able to bypass the MIDI layer altogether, speeding up the proceedings. This isn’t usually a problem, though one pitfall to be aware of is that you must set the external synth to the same pitch bend range as the GR-55, otherwise any bent or slurred notes will result in sonic chaos! You also need to be aware that most synths and modules come set up in Poly MIDI mode, which means you can’t bend each string independently. This is fine for simple chordal or melody work, but if you want to use regular guitar bending techniques and have the synth respond in the correct manner, you’ll need to set it to Mono mode so that it behaves as six separate mono synths receiving on six separate MIDI channels. This is easy enough to do on most polyphonic synths. If this is something you plan to do in the studio on a regular basis, the easiest option is to create a special song template in your DAW for use with MIDI guitar where you already have some software instruments loaded and set up appropriately.

Now it might be that while all this sounds very appealing, you’ve tried a guitar synth in a shop or played with a friend’s system and found it less playable than you expected. While it is true that the sampled synth sounds react better to a reasonably clean and positive playing style, the most common cause of poor performance is the GK pickup being installed incorrectly. The spacing between the pickup and strings is quite important and the mounting kit comes with spacers to make this easy to achieve. If you follow the guidelines in the manual you should end up with a system that behaves consistently well. It only takes a few minutes to get this right and you only have to do it once. With the pickup correctly installed, there’s then a simple setup procedure to ensure all the strings are equally sensitive, but again very quick and easy. And if you have more than one Roland Ready guitar, no problem as the GR-55 can store setup details for all of them up to a maximum of 10 guitars. I like that the GR-55 is designed for guitar players, not techno-nerds!

I’m not a keyboard player — I can’t get my head around something that forces you to learn a new scale shape every time you change key, so in the studio I use my Roland guitar-to-MIDI stuff all the time to play synth parts. You just have to remember to play in a way that is appropriate to the sound you’ve chosen — Steve Vai style speed licks on a Tuba or bowed bass patch really don’t translate very well! Live though, I love the COSM modelled 12-strings, the different amp sounds, the effects, the ability to hold pad sounds under my usual guitar sound and the ability to have something like an organ sound layered behind the guitar. Even used at a very basic level the GR-55 can add a completely new dimension to your sound and leave your audience wondering exactly how you did it, and if you play in a covers band and need a custom guitar sound for every song, it will do that too.