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Roland GR20

Guitar Synthesizer
Published January 2005
By Paul White

Roland GR20Photo: Mark Ewing

Roland's affordable new guitar synth incorporates improved pitch tracking, and comes bundled with the latest GK-series pickup as standard.

Roland are one of the few music companies continuing to pursue the guitar synthesizer as a mainstream instrument category, which is commendable, as many guitarists tend to be suspicious both of the way guitar synths track their playing and of synthesis itself. To help woo these players, the GR20 is Roland's most affordable and easy-to-use guitar synthesizer to date, yet it also contains a huge library of categorised synthesizer sounds stored as presets that can be adjusted using very few controls and then stored as user patches if required. A new all-digital pitch-tracking system replaces the hybrid analogue approach used on earlier instruments, and there's also a new, more up-to-date hex pickup called the GK3 that comes bundled with the GR20.

As ever, a split pickup is an essential part of the system, as pitch-tracking can only work on a monophonic source, so each string has to be treated individually. This pickup can be fitted to most steel-string (six-string) guitars, where it must be mounted as close to the bridge as possible and spaced from the strings fairly precisely as described in the setup instructions. Once this is done, a simple adjustment of sensitivity to allow for string gauge and playing style is all that's needed. This function is deemed so important that it now has its own button. The string picking intensity is shown on an LED level meter, and you simply work through all six strings adjusting the sensitivity so that the top LED only comes on when you play hard. A number of commercial instruments are available with a GK3 pickup system built in, and any of these may also be used with the GR20. Furthermore, a new software revision allows bass guitars fitted with a Roland GK pickup system to be used — the special bass mode is entered by holding down a key combination while powering up. I didn't get a chance to try this myself, as no bass pickup was supplied, but I saw it demonstrated recently, and it seemed to work extremely well with no apparent tracking or glitching issues.

Compact Stomp-box Casing

The GR20 comes as a distinctively Roland-styled stomp box with two footswitches, a pedal, and just a small handful of knobs and buttons. Depending on the patch, the pedal is used to adjust volume or some other variable function, such as filter frequency. An 11-way rotary switch selects one of ten categorised sound banks (strings, brass, wind, synths, and so on) or the user bank, and each bank typically offers between 31 and 93 patches. In all there are over 450 patches based on Roland's latest generation of sample-based synthesis, and these can be further modified using simple envelope and filter controls, transposition, and onboard delay, reverb, and chorus effects. Patch changes based on these few controls can be saved into the user bank, or you could utilise the user bank simply as a means of organising your performance patches in sequence.

The unit also has the capability to create a MIDI patch map in order to link external MIDI effects to specific GR20 patches. By default, the two footswitches control the Glide effect and the all-important Hold function, but they can also be set to increment or decrement patches if preferred. However, the two buttons on the pickup control unit can be used to step through patches, as can the data knob on the GR20, so in most cases it makes sense to leave the pedals set to Hold and Glide.

As with previous units, the guitar's own output can be routed via the pickup control box to save having two cables hanging from the guitar, and the control box includes a three-way switch to allow the user to select guitar only, guitar and synth, or synth only from the unit. The synth volume can be adjusted from the pickup control unit.

One sign of cost-cutting is that, once you've selected a sound bank, the patches within that bank are displayed only by number using a two-digit display to the left of the main data-entry knob. However, the unit does include a very accurate tuner that uses the status LEDs above the knobs as indicators. When the central green LED lights, the string is in tune. Power comes from an external PSU unit, and a special multi-pin cable connects the GK3 pickup to the floor unit, carrying both the pickup signals and the guitar signal, provided that you plug the guitar output into the special guitar input on the GK3. The guitar signal emerges from a separate Guitar Out jack on the GR20, though there's also a mix input that can be used as an effects return if you need to use external effects. This input can be used to add other sources, too, such as a backing track, to your mix. As the unit is designed for both studio and live performance, there are two output settings that EQ the synth for use with a guitar amp or a full-range PA/recording system. One interesting touch is that each of the patch category switch positions 'remembers' which preset number was selected last time you used it, which could be useful in a performance situation, though this information vanishes when the machine is switched off.

Although a huge range of sounds is included, the floor unit also has MIDI In and Out connectors, allowing the MIDI data to be recorded to a sequencer and enabling sequencer data to control the GR20's internal sounds. A Local Off mode is available for sequencer work. It is important to note that the pitch-bend range of the GR20 is set at 24 semitones to allow the system to cover string bends and glides with maximum resolution, so any external synth must also be set to the same range unless you're only playing chromatically (no bends).

Roland GR20Photo: Mark Ewing

Sound Editing

Once a patch has been loaded, it can be edited in a fairly limited way, and unlike the more costly GR33, you can't layer sounds. Envelope modifications can be made via Attack and Release knobs, where the changes are generally applied to the original envelope of the patch with both positive and negative ranges of adjustment. A single knob selects delay or reverb and enables the amount to be adjusted, while the chorus effect has a knob of its own. There's also a separate knob for the patch level. Two alternate rows of functions are printed above the knobs, and each row has a selector switch with status LED to show which set of functions is currently being controlled. Pressing the selector button repeatedly steps the status LED along the row to show which parameter will be changed when the data wheel is turned. The lower row allows Filter Brightness (frequency), Resonance, Transpose Value, and Play Feel to be controlled, while the upper row accesses system setup functions such as the output base MIDI channel (channels run sequentially from the bottom string, as each string sends on a different MIDI channel), the switch modes, patch linking, and choice of output type. Most of these turn out to be pretty self-explanatory, and it is a tribute to Roland that the manual extends to only 33 pages before you hit the patch lists and MIDI specifications.

Although sound-editing parameters are important, the real key to getting the best out of this kind of unit is to understand the Play Feel and Hold parameters, both of which are set individually per patch. On other GR models, you're also able to select whether the notes play in semitone steps or whether you can bend notes, but here the choice is made for you depending on the patch selected. For example, a grand piano has no pitch-bend unless you have a very large jack and a solid floor, so the piano patches tend to be chromatic!

Play Feel affects the way the sounds respond to picking intensity, where settings one to four give progressively less dynamic range. The fifth setting, 'ND', means everything plays at the same level, so there are no dynamics, and this may be suitable for organ patches or harpsichords, which also have no natural dynamics. A sixth setting denoted as 'ST' suppresses low-velocity notes to help tidy up playing when you're strumming, though fast strumming is something that no guitar synth responds to particularly well. Suitable settings are chosen for the preset patches, so if you wish to change one, you have to re-save the modified patch into a user memory.

GK3 Pickup System

Roland GR20Photo: Mark Ewing

Although it offers more or less the same features as Roland's previous GK2 system, and the pickup part is similar in size and shape, the GK3's control box has undergone a major re-style and comes with a bracket that allows it to be fixed using the body strap peg on most guitars. Alternatively, double-sided sticky pads work fine, and plenty of fixing accessories are included. The box part of the system has the same two buttons, a three-way selector switch, and a volume knob, but the layout is a little more ergonomic than it was previously. The guitar can be plugged in using the short jack lead supplied, which has a quarter-inch jack at the pickup end rather than the previous mini-jack.

The mounting kit for the pickup includes self-adhesive shims and double-sided pads as well as screws, but there's now also a little bracket that slots over two-post bridge supports (Les Paul-style) to hold the pickup in place without screws or adhesive. The pickup then screws to this bracket via the included rubber tube washers or springs that compress to allow the pickup height adjustment to be fine-tuned. Note that the pickup is a humbucking design to help reduce interference from computer monitors and other sources. That said, in my experience sitting too close to glass CRT monitors can still cause tracking problems, even though the result of the interference is not audible as hum or buzz.

Using The Hold Function

The Hold function is the key to effective performance with a guitar synth, as you can use it to sustain any chord while you reposition your hands for the next one, thereby avoiding gaps and glitches. There are four Hold modes in all, each one designed for a specific style of playing. The first effectively holds any note you play until you play a new note on that string, after which the new note takes over. This mode is fantastically effective for playing orchestral string parts, and the results are more realistic than anything I've been able to achieve from a keyboard, as it's easy to create moving melodies over static notes or chords played on other strings.

The second Hold mode works more conventionally, holding any notes that are playing, while preventing further notes from being played. This is good for playing clean organ parts based on chord changes, or for freezing chords while you noodle over the top using the normal guitar sound. The third mode holds the notes that are being played, while allowing you to play notes on the remaining strings without them being held. This is again good for freezing chords and then noodling over the top, this time playing melodies on the free strings. The final hold mode holds all the notes that were playing when hit the pedal, and also holds subsequent notes you may play on the remaining strings.

You can also select which effect or parameter will be controlled by the pedal, the choices being volume, filter frequency, effect level, or various degrees of pitch-bend. My only concern is that the presets don't seem to provide visual information as to which Hold or Play Feel mode is currently active.

Playability

The synth's sounds themselves are reminiscent of Roland's JV/XV range of instruments, and are arranged into Piano, Organ/Keyboard, Bass/Guitar, Brass, Wind, Strings/Orchestral, Synth/Lead, Voice/Pad, Ethnic, and Rhythm/Percussion categories. Many old favourites are in evidence here, though the patches have been selected with guitar players in mind. The easiest way to move through a bank is to use the up/down buttons on the GK3 pickup control box, or the data knob on the GR20. It is also worth pointing out at this stage that the GR20 works equally well with the older GK2 pickup system, which has the same arrangement of switches.

The moody sax is particularly good, as are many of the strings, and there's even a Mellotron-like string pad in there somewhere. In fact, the only sounds that invariably disappoint are those based on guitars, as they rarely sound anything like the real thing due to the influence playing style has on real guitar sounds. On the other hand, the bass guitars are really good. There are also some interesting splits, where the low one or two strings play different sounds to the others, and this is particularly effective where a bass sound has been added on the lower strings along with an octave of downward transposition. Notably absent, though, were many (or indeed any) velocity-switched sounds, so no matter what you play you always seem to get the same sound, just louder or quieter depending on how hard you pick.

I found the playability to be very similar to that of my GR33, which is to say that tracking delay is no longer a significant issue, and the quality of note recognition is extremely good, even when you accidentally hit a pinched harmonic. Where it does fall down slightly is that notes sometimes re-trigger at a low velocity when you lift your fingers from the strings, especially at lower fret positions, and this is most obvious with percussive sounds such as piano. All Roland's MIDI guitar synths have suffered from this, so vulnerable sounds have to be played with extra care, and here the hold functions can help, as can damping the strings with your hand when lifting off from chords. It would be rather nice if the tracking software included some intelligent algorithms to strip out low-velocity hammer-offs to open strings, as these are almost always the result of fingering noise.

The easiest sounds to manage are things like strings that have a slower attack time, though newcomers to guitar synthesis sometimes complain that the sounds can't keep up with them. This isn't a fault of the synth, but simply the way different instruments 'speak'. If you try to play a fast guitar run on a tuba, it won't sound right because the natural attack of a tuba (real or synthesized) is too slow to permit it. You have to get the characteristics of the instrument you're using into your head and try to play accordingly, and that often means slowing down, and playing with more thought. On the whole, fairly clean players should have no trouble adapting to the GR20, though more sloppy players may be able to goad the system into glitching occasionally.

External MIDI

My tests with external MIDI devices confirmed that the internally generated sounds respond rather more positively than external MIDI sounds, mainly because MIDI is bypassed when the internal sounds are being used. Nevertheless, the GR20 does provide a practical way for the guitarist to make better use of MIDI sequencing, and you can easily identify and strip out any rogue low-velocity notes in your sequencer's event editors. The best way to work is to control six monophonic synths on six separate MIDI channels, as this allows independent string bending (provided that your synth can be set to a bend range of 24 semitones), but you can also work in the simpler Poly mode if you only want to play chromatic parts or single melody lines with string bending.

The Score

With just a little practice, it is easy to get great-sounding results from this simple instrument, and because many sounds respond to string bending, you can apply much more natural vibrato than would ever be possible using a keyboard. Sax and solo string parts can be made to sound particularly realistic this way, but I can't emphasise too strongly that making good use of the hold function is the real key to creating a convincing performance where you need sustained notes. Not every patch is staggeringly realistic or expressive, but enough of them are that many people will get by perfectly well using just the internal sounds.

While guitar synthesis isn't for everybody, the GR20 is about as good as this technology gets at present, and it is also very affordable and easy to operate — you can learn all you need to know in half an hour. There's no need for guitar players to worry about the intricacies of synthesis, because there are so many great presets ready to go and the tracking is both fast and accurate provided that you play reasonably cleanly and get your fingers down before you pluck, rather than slightly after. Claims that you don't need to adapt your playing technique at all are somewhat exaggerated, but playing cleanly without 'digging in' will avoid trouble most of the time.

At one time guitar synths were so expensive that you had to be really dedicated to want to own one, but now that the UK price has dropped, and now that the pickup comes as part of the package, any guitar player can use the guitar as an input device for a sequencer as well using it in the obvious live synthesis applications. If bad experiences with earlier guitar synths have put you off, put all that behind you and give the GR20 a chance. I think you'll be impressed.

Published January 2005