Just when it seemed the sampling keyboard contest was a one-horse race, the Prophet people come up with an instrument that combines a polyphonic synth with a midi-controlled sampler. We've had a sneak preview of the Prophet 2000, and we like what we see.

In the world of sound-sampling, nothing, and nobody, is safe. A year ago, you had to look hard to find something that could store external sounds within digital memory and let you control the pitch of that sound from a keyboard, but which cost less than £10,000. Now, there's a mass of manufacturers queuing up to offer precisely that, the latest of them being the pioneer of the programmable polysynth, Sequential Circuits.

It's from Sequential's San Jose, California home that the design of the new Prophet 2000 keyboard originates, and it's there that the £2000 instrument will be made (production should be in full swing by the time you read this). But given the prowess with which Sequential have produced analogue synthesisers in the past (Prophet 5 and T8, Pro One), it isn't surprising that they should be clinging to that technology even now. In fact, their obstinacy is a blessing in disguise, for the 'synth' bit of the Prophet 2000 is the biggest single factor that separates the American newcomer from its immediate competition - present and, as far as we know, future.

To begin with, Sequential's design people have recognised that the worst thing keyboard players can have when they switch on an instrument is a machine with no sound in it. Thus, the new Prophet (I make it the fifth SCI keyboard to bear the name) comes equipped with a selection of basic analogue synth sounds, stored away in ROM away from prying programmers' imaginations. The sounds are generated using six fairly straightforward analogue waveforms, and you can edit them using a reasonably comprehensive array of familiar user-adjustable synth parameters. These include two ADSR envelope sections (one for the filter, the other for the amplifier) that include a footswitch-activated second release time parameter, and a single LFO with six variable parameters, viz rate, initial amount, velocity amount, amplitude, filter and vibrato.

Some of the preset sounds aren't bad at all, with the piano-type voices standing out as belying their humble synthetic origins. In general, the ROM voices sound fairly modern but very un-Sequential. Those who dreamed of a sampling keyboard that had a Prophet 5's synth voicing circuitry built in are in for something of a rude awakening when they power up the 2000 - but the dealers should love it for its instant 'demonstratability'.

The synth section on its own would scarcely be worth two grand, though, so the sampling end of things has to be good, too. And it is, even though the model we took a peek at was a pre-production prototype with a lot of software still to be written and more than a few question marks hovering over things like MIDI spec and compatibility.

For the spec-hungry, the Prophet 2000 gives the user a handy (and as yet unmatched) degree of control over parameters such as sample length and bandwidth, sampling rate, input level and so on. The maximum sample time is a highly respectable eight seconds (compared with the Mirage's four), this at a bandwidth of 8kHz. If you value quality over quantity, you can store, say, a three-second sample with a frequency response of 20kHz. The sampling rate is also variable, though you have to select from three preset values rather than adjust the rate continuously. The Ensoniq scores here, but its highest rate is nothing like the fastest of the Prophet's trio: 15kHz, 31kHz and 41 kHz.

Sampling on the 2000 seems a simple enough exercise, aided by the machine's front panel LEDs doubling as peak level indicators, and the alphanumeric display volunteering information on things like threshold and pitch. Knowing just what sort of sample rate, threshold level and input level you need is a matter of trial and error, but that's true of all sampling instruments, really. Still, there's no doubt the new Prophet could do with having a bit more in the way of data display. In the age of the multi-character LCD and the full-colour CRT, the 2000's complement of red LEDs seems decidedly mean - not to mention limited in the amount of information it can provide at any one time. Plans are afoot for the writing of MIDI-based sampling/editing software for various home computers both in Europe and in the States, but that isn't going to materialise for a while, and not everybody has a micro...

Soundwise, and replaying samples taken from the line output of a fairly dodgy cassette recorder, the Prophet held its head well above water. And sampling a digital brass sound from a certain Far Eastern FM polysynth reviewed elsewhere this issue, you had to listen hard to notice the difference.

If you're at all interested in sustaining your sound samples, looping has got to be high on your list of sample-manipulation functions, and the Prophet 2000 is well equipped in this department. It offers not one but two looping facilities for each sample, so there are a total of four user-selectable loop points to be considered: sustain start, sustain end, release start and release end. So even without the envelope controls of the Prophet's synth section, you can take quite major decisions on how your sample is going to behave over time - and act on them without encountering too much operational hassle.

But the Prophet 2000 is likely to win most of its supporters on account of the sheer number of possibilities thrown up by the combination of synth and sampler. Sadly, we scarcely scratched the surface of what might be possible in the afternoon (nay, less) that the new machine was in our grubby paws, so objective comment on those possibilities will have to wait.

One thing is certain. Sequential have made sure you can use your creations to really 'perform' with by including a number of scintillating 'performance' options. Not only does the 2000's five-octave keyboard have a weighted action and velocity-sensitivity (routable to both filter and amplitude envelopes), but it's splittable at any point you see fit, and you can configure its eight-note polyphony to perform any number of split/layer operations, all transferable/receivable over MIDI. Especially neat is a mapping function that allows you to arrange two layered samples so that the first is audible under normal playing pressure, while the second comes into play as soon as you strike the keys with greater velocity.

None of these performance configurations would be much use if you had to set them up each time you powered up the Prophet 2000, but like most of the machine's variable parameters, their values are all storable to disk, courtesy of a built-in 3.5" microfloppy disk drive. And unlike the Mirage, which forces you to buy ready-formatted disks at vast extra expense, the 2000's operating system does the formatting itself, so all you need buy is standard, unformatted blank disks. Sequential will also be offering an extensive library of factory samples, for the lazy, the curious and the pressured.

When can you expect to see the Prophet at your friendly neighbourhood music store? The beginning of October, say Sequential, though the initial shipment isn't going to be a big one, as everybody expects demand for the synth/sampler to outstrip supply comfortably for at least the first six months of its availability. They're probably right, though we're going to make sure we get our hands on a production model for a fortnight or so before we commit ourselves to heaps of unmitigated praise. By that time, the internal software should be complete, and there's talk that its capabilities will include transmission and reception of sample data over MIDI, a user-variable MIDI baud rate, and multi-timbrality à la Sequential's recent polysynths.

One to watch, definitely.