If you've always hated guitar synthesizers, maybe it's because you've never liked guitar synth controllers. Now may be the time to change your mind.

The whole idea of guitar synthesis has a patchy history. After a shaky beginning (remember the old GR500 'Mindblower'? The most mindblowing aspect was its impenetrable forest of control knobs) Roland's later GR100 and GR300 synths settled down to a certain standard of performance response which most players found acceptable.

Problems did remain, however, mainly in the difficulty of changing sounds quickly and reproducing favourite patches. Roland took quite a time to produce their programmable guitar synth, the GR700, and when it did arrive it was firmly based on existing keyboard technology. The GR700 floor unit is basically a JX3P synth with velocity sensitivity — or, if you like, an MKS-30 (Planet S) module in a foot-controlled format.

What did remain from the previous designs was the method of interfacing to the guitar controller. A custom 24-pin socket and lead connect the guitar to the synth, and apart from carrying note information from the strings, this lead relays volume settings and (in the case of the programmable GR700 synth) even parameter information.

So it's possible to use one of the older G202, G303, G505 or G808 guitar controllers on the new GR700 synth — but why would you want to give up the delights of the bizarrely-shaped G707 controller, with its high-tech second neck? Well, there are a couple of possible reasons — some guitarists find the G707 just doesn't fit in with their visual style, and others find its straight guitar sound a little bland. After all, that second neck is there to improve tracking specifically by cutting down on overtones.

New England Digital were the first company to expand the range of options in the Roland guitar synth system, but they went about it the wrong way — by taking the existing G808 controller and making it interface to a £40,000 synthesizer, the NED Synclavier. Then Steinberger saw the light and announced a guitar, built under license from Roland and fitted with the custom pickup and output socket necessary to control their guitar synths. And now Gibson have done very much the same thing, announcing a new edition of their established Explorer guitar fitted with a Roland synth pickup — it's called the Explorer Synth.

If you want a really high-class guitar with the option of using it as a synth controller, this may be the one to go for, and you can use any of the (discontinued) GR100, GR300, GR500 or (new) GR700 synth units. The simpler 100 offers just a few variations of sustain and tone of the synth oscillators but does allow you to mix guitar and synth effects, while the 300 has many options including Glide, Interval, Tuning and so on. The older GR500 popularised by Steve Hackett has bass, lead and poly ensemble sections while the latest GR700, as we've mentioned, is a fully programmable synth. But let's look at the new controller in detail first, and get back to the synth later.

Gibson Explorer Synth

The new Gibson has hardly become cluttered by its conversion to synth use. While the functions of its main controls are slightly changed, there are only three additional controls, an extra third pickup, and of course that multipin output sunk into the side of the guitar.

The model we looked at was in glossy white, a beautiful finish and quite typical of the company. Fittings were in chrome and the four standard controls were in gold. The three-way pickup selector — placed as usual on the lower horn of the Explorer's unusually-shaped body — was a conventional black plastic toggle switch.

Apart from the usual two single-coil pickups the Explorer has a third pickup situated right up against the bridge. This is the synth pickup, a narrow black strip with individual pole pieces which doesn't intrude on the guitar's styling at all. On the sides of the bridge pickup are two metallic buttons which react at a touch to bring in modulation options.

The four gold controls are Master Volume, Guitar Tone, Guitar/Synth Balance and Synth Tone. The three new controls consist of two black knobs and a black metal three-way toggle.

The toggle is the Mode Selector (Guitar Only, Guitar and Synth, and Overdrive Guitar and Synth) with a heavier picking action capable of overdriving the guitar being needed to play the synth in the third mode.

The Guitar/Synth Balance knob simply balances the guitar and synth volumes in Modes Two and Three, and is inactive in Mode One.

There are various ways to 'get at' the guitar and synth sounds. Next to the multipin connector on the guitar is a standard jack which simply puts out the guitar sound alone, so you can amplify the guitar separately as long as you don't mind having two leads dangling from your axe. If you're using the GR700 synth, you'll find there's also a Guitar Only jack output on that, so you could take the guitar sound from there and even have some effects pedals connected after the synth unit.

Additionally, the GR700 has jack and XLR mixed outputs which can be used in mono or stereo (for the synth's chorus functions), so the options are endless. You could even connect more than one guitar output up to different effects units and switch between them.

Back to the guitar itself though. Pearl dot markers, rear strap toggle, conventional Gibson bridge, and despite a large chunk of electronics being hidden away inside, it still balances. Still heavy though, and of course lacking a tremolo, which is a shame since one of the GR700's best tricks is a Chromatic (quantised) bend which is at its most impressive when controlled by a whammy bar. Why not choose a more down-market guitar with the luxury of tremolo for the guitar synth treatment? Possibly because it's difficult enough to get a guitar synth to track pitches without adding the detuning problems inherent in using a tremolo of any kind.

The Explorer plays smoothly, perhaps with a bias towards the Heavy metal side of things, but what's wrong with that? Having a single tone control can be limiting, but the basic power of the guitar's sound helps to make up for that. Once you use Mode Two or Mode Three you're into a new world of sounds anyway.

If you don't like the basic tone of a synth sound once you've mixed it in, you can hit the Edit footswitch on the GR700 floor unit and the fourth control knob on the Explorer becomes a filter control, allowing you to adjust the basic tone of the synth sounds on a scale of 0 to 99 (on the older synths you can control Resonance instead of parameter levels with the edit knob). The synth will respond to most of the usual playing techniques and adds a few of its own such as Chromatic Glide, but if your fingers are tired of playing vibratos you might be particularly interested in the modulation facilities.

Whatever effect is programmed into each synth patch, at whatever rate, can be brought in by turning the furthest black knob from your hand up, and touching the metal button on the bridge pickup. Effects can include vibrato, tremolo, pulse width modulation, and many indescribable synth treatments.

The Explorer allows you to mix quickly between guitar and synth sounds and to make the most of the interface between the two. But now, on to what the GR700 can offer you...

Roland GR700 Guitar Synth

As we've mentioned, the GR700 is basically a velocity-sensitive Roland JX3P in a floor mounting format. However, you can't control it from a synth or MIDI sequencer since it has no MIDI In socket — the Roland synth pickup is hexaphonic, the string information going straight from the pick up to each voice circuit, and so there's no facility which would enable different notes played on a keyboard to be assigned to each synth voice.

On the other hand, the GR700 does have a MIDI Out socket, so you could use it to control a Yamaha DX7 or any other MIDI synth from your guitar controller. Reports on the accuracy of such techniques vary, but it is quite a common practice nowadays (this is beginning to sound like a sex manual...)

The GR-700 has eight numbered footswitches, three more footswitches marked Edit, Hold and Bank, a large LED display and a number of touch membrane switches. It stores 64 sounds (you can store more on a memory cartridge which plugs into the back panel, or dump sounds to cassette to create your own library) and sounds are called up almost instantaneously by pressing Bank, a bank number, then a patch number. If you want to stay in the same bank of eight sounds you only need to hit one switch for a new patch number.

The sounds are tremendously varied and can be very powerful. Strings and brass are obvious options, but you can also produce clanging metallic effects and sweeps, special effects sounds such as wind and surf, percussive sounds such as clavinet or Rock organ, and screaming lead sounds.

The factory presets give a good selection, but of course you'll want to edit many of these sounds to suit your exact needs. You can do this from the guitar by hitting Edit, choosing a parameter number with the footswitches, and turning the Edit control on the guitar until you have the effect you want. There's a chart in the synth handbook which tells you which numbers to choose for which parameter (say, 21 for Oscillator one Pitch, or 33 for Attack time) and also a sticker which you can put on the synth to remind you of these numbers.

Alternatively you could lash out on the PG-200 Programmer, a little black box covered in knobs which allows you to change as many parameters as you like as quickly as you like. Either way, when you've created a new sound you can store it away or save it to tape or cartridge.

Various options exist while you're actually playing the guitar synth — you can switch any combination of strings to synth mode so that the others just produce the normal guitar sound, and can stand on the Hold switch so that any synth notes sounded will hold on continuously. With a little imagination you could program patches in different keys, holding them on as desired, soloing over them and changing key by changing to a new patch.

Since the GR700 is velocity-sensitive you can program Oscillator, Filter and/or Amplifier response in each patch, which can produce a wide range or technique-dependent effects. This takes the guitar synth out of the realms of the electronic and makes it a truly expressive instrument.

In fact each patch allows every string to respond individually to the Synth Voices, to the Hold Switch, and to the Pitch Bend pedals mentioned below. So the individual response of each patch is limited only by your imagination!

There are a few effects which can't be reproduced (often depending on the exact patch chosen), and you'll have to learn some new playing techniques. Hammering on has to be fairly positive if the synth is to respond, and hammering off frequently doesn't work — you'll sometimes have to give the string an extra twang at this point. As previously mentioned, your string bends can be quantised so that the synth only responds in whole semitones, although this is more impressive on a guitar with a tremolo.

The GR700's rear panel positively bristles with sockets which can improve your sound. Apart from all the audio outputs mentioned, there are pedal inputs for the oscillators and filter, so you can bend synth notes (up or down, programmably for each patch) to an almost absurd degree, and also controls the filter for wah-wah type effects The GR700 is a unique instrument, and one which needs to be learned like any other. Obviously you can get some sounds out of it instantaneously — that's the massive advantage of programmability — but don't be put off by any glitches in response the first time you play one. 90 per cent of these vanish with only a slight adjustment of playing technique.

Conclusions

Since we're going on about playing technique, it's only fair to point out that Roland knew what they were doing when they designed the G707. The double-necked controller is optimised for guitar synth use, and no conventional guitar, whether specially fitted with a synth pick up or marketed with it in place, is going to compare (the Steinberger may be an exception — we'll have to see).

Put simply, however careful your technique, the Explorer Synth doesn't control the GR700 as well as does the G707. But everybody must have known that when the idea was first mooted, and so there's an obvious trade-off in operation.

The Explorer's a beautiful guitar. If you're going to spend a lot of money on an HM guitar you could well be looking at Explorers anyway, and if you're in a certain kind of band you don't want to be seen with a rather hi-tech controller with a slightly bland sound. The trade-off is that you're going to have a few percent more glitches with the Gibson, and you're going to have to modify your technique fractionally more to make sure that the GR700 performs at its best when controlled from it.

Now let's talk money. Rosetti in the UK don't hold a large stock of Gibson guitars, but any dealer can order the Explorer Synth specially, with a delivery time of six to eight weeks. Price for the guitar is around £850-£900. As for the GR700, retail is about £1,650 so the whole package doesn't come cheap.

Any problems? You don't have to worry about the synth output lead for stage purposes — it's not all that bulky, and it's very securely locked in place. You don't have to worry about being able to see the synth — the LED display really is very large.

Just one point. It would be nice if somebody would market a scanning convertor from a 24-pin output directly to MIDI, so you could use any suitably equipped guitar to control any MIDI synth. Then we'd really see some guitar synthesizing going on.

RRP: £900 approx.

Rosetti/Gibson, (Contact Details).
Roland UK, (Contact Details).