THIS COULD BE the synthesizer of the future... or maybe not. Either way, the Alpha Juno 1 has already raised eyebrows by turning up at a very peculiar time of year, around two and a half months before the Frankfurt Music Fair. Something to do with the customary Japanese willpower breaking down in the face of an uncontrollable urge to show their latest baby to the world...

Now the Alpha Juno 1 (JU-1 if you like — I certainly prefer it, it saves typewriter ribbon) is not the most devastatingly innovative synth of recent months, but it does help to point the way ahead. Basically the machine is a cut-down Juno 106 (the Juno's destined to stay in the catalogue for some time though) with some additional facilities and a new control system based on the alpha Dial. Going for a single-knob design is unlike Roland (although it is possible to edit both the JX-3P and JX-8P synths with one control) but the alpha Dial is a new animal entirely, both selecting parameters and altering their values.

In fact this continuously-rotating dial idea is familiar from the old Moog Source and from the up-market Synclavier, but on both those instruments the selection of the parameter you're working on was through the familiar expensive control panel. The JU-1 has a few conventional knobs and switches, but not many — that's why it's relatively cheap.

Actually calling up sounds couldn't be more straightforward. The synth has two sets of eight membrane switches similar to those on the Yamaha DX7, which allow you to select eight banks of eight programmable sounds. Another pair of membrane switches takes you from Program to Preset mode — so there are 64 programmable and 64 preset sounds available. The presets can only be edited temporarily, but of course the programmable memories are yours to use and abuse as you like.

To the left of the membrane panel is a handy tell-it-all backlit LCD display which gives names for each sound, patch numbers, and parameter and level information in the Edit mode. The LCD display and the Alpha Dial are really the twin centres of operation on the JU-1 (as would be the corresponding controls on any digital access synth), and on the whole they should be adequate to keep the user informed as to what's going on inside the machine.

The main problem in using the Alpha Dial is that there are so many parameters available. Apart from the familiar facilities of the Juno 106 there are expanded possibilities in the memory, MIDI and oscillator areas, and that means a lot of parameters to delve through in order to find the one you want to fiddle with.

Probably this process will speed up with familiarity, and remember that the alpha Dial is of the infinitely rotating variety so you can theoretically get from anywhere to anywhere else in the same amount of time (I think?!?).

But Roland have been wise enough to make the most frequently used parameters more easily accessible. To the left of the LCD are eight membrane switches for Tone Modify (Mod Rate, Mod Depth, Brilliance and Env Time) and for Edit (Parameter Select, Value, Name and Write). The Tone Modify controls fairly obviously allow you to modify the vibrato or other modulation, the filter setting or decay of a sound quickly, without going into Edit mode, which is enormously useful.

The other four functions mentioned, those under the general heading of "Edit", are those concerned with getting at all the more detailed parameters, altering their values, naming altered sounds and filing them away. If you do go into Edit Parameter you then go to the alpha Dial and give it a spin — it's like some kind of TV quiz show, and while it may be slow, at least it doesn't involve inviting Bruce Forsyth into your home.

On the whole the performance controls are faster to use, as they would have to be for live applications. You can switch in Portamento or Chord Memory, which allows you to play a chord on the keyboard and reproduce it from each key with a single finger from then on. Unusually, it's also possible to program a chord as part of a patch, although it's a slightly more involved procedure.

You can alter the pitch of the keyboard down one octave using a single control, although in fact there's more variability available in the individual programmed sounds. But being able to alter octaves is vital, because you'll have noticed that the JU-1 only has a four-octave keyboard. This may or may not provide a major problem for you, depending mainly on whether you want to play Chopin on a polysynth, but we'll come back to this question later.

It's big brother the Juno-2, also just released, offers a longer keyboard, RAM-pack memory, velocity sensitivity, and a few other odds and ends, but it's another couple of hundred quid.

But back to the JU-1.

Of course, you could free yourself from the restrictions of the JU-1's short keyboard by controlling it from some other MIDI synth, and this is where we start to come across hints of the JU-1's role as a MIDI expander; Because the unit has a very full set of MIDI functions, and in fact responds to velocity and after-touch information sent over MIDI. It can work in MIDI Omni or Poly Modes, responding to information on all channels or any of the 16 individual MIDI channels, and can transmit patches over MIDI to other JU-1 units, or store patches to tape.

Taking a leaf from the DX7's book, the JU-1 also displays its envelope capabilities in all their glory on a chart on the right-hand side of the control panel. That's just as well, because the JU-1 has a multistage envelope new to Roland, which does mean that there are a couple of new details to learn in each sound.

You'll also find more oscillator options than ever before, with a selection of three pulse waves combinable, five sawtooth waves, and a sub oscillator with six pulse wave options. All this means that the standard Juno repertoire of brass, synth, swirly string and other sounds are still there, while some greater subtleties of tone and development of sounds have been added.

Hardly a revolution, but at least an indication that Roland aren't standing still, even in the budget keyboard area.

But a four-octave keyboard? Miniature keys would have been understandable in view of the success of the Casio CZ-101 and the launch of Yamaha's tiny DX-100, but Roland seem more committed to playability at all costs. The message seems to be that you may have fewer keys than usual, but at least they're all the right size!

But the fact that velocity and after-touch response are available from external MIDI sources does tend to confirm the JU-1's role as an expander. One obvious application would be to add it to a DX7 to give an ideal combination of sharp, digital sounds and the lusher analog sounds for which Roland have become famous. That setup would take full advantage of the DX7's velocity and pressure control; but still leave the option of playing some parts on the Juno's own keyboard without having to shrink your fingers in bleach overnight.

The Alpha Juno 1 does retain the advantage of being attractive to the beginner who may keep it on as part of an expanded setup though. £575 (or less) isn't much to pay for a very respectable polysynth, and the less sophisticated composer isn't likely to be too bothered about that odd missing octave of keys.

But this budget approach doesn't get too much in the way of the easy operation of the synth. You can sit down at the JU-1 and play it quite happily if you like, or you can tuck it relatively out of the way and use it as an expander, perhaps for a favourite FM synth or perhaps as part of a large MIDI compositional system (Roland have some interesting computer packages coming out soon along those lines).

Overall the JU-1 is (as they used to say in those packet sauce adverts) plain but nice. It's bound to have a reasonable level of sales, and while it won't set the world on fire, the individual user may well find that it can start a flame in your heart.

ROLAND Alpha Juno 1: £575