Two months ago we previewed the Prophet 2000 sampling keyboard and conveyed some favourable first impressions. Now we've been working with one for some time, and find most of those impressions confirmed in long-term reality.

A name has returned from synthesiser history. A name which was synonymous with professional polysynths in the days when the DX7 wasn't even a twinkle in John Chowning's eye, let alone a gleam in the Yamaha salesman's. Maybe I'm being a bit overdramatic, but it does seem like a long time since the days when every keyboard player wanted a Prophet 5. Actually, it's only been two or three years, but a week is getting to be a long time in electronic music hardware.

Anyway, the Prophet name has now returned, and Sequential (or SCI as they were known in the days of the Prophet 5, 10, T8 and 600) are obviously hoping its revival will bring about a revival in their fortunes. For truth to tell, some of the company's recent instruments have been less than a complete success. Uninspiring, half-baked machines, developed too quickly and sold too cheaply, were never likely to live up to the standard set by the Prophets and, more recently, the excellent Drumtraks digital drum machine.

No. Sequential's future lies not in producing Californian Casio-beaters. It lies in the production of sampling keyboards, something the Californians already do rather well in the shape of E-mu Systems and their Emulators.

The Prophet 2000 had been quite a closely-guarded secret until a couple of months back, when two or three machines made their way over to Europe, and one of them did the rounds of the music magazines in the care of a Sequential salesperson. Since that time, it's been down to me to demonstrate the machine to a few would-be customers, a job that's entailed having to learn a lot about the 2000 in very little time.

It's been productive, though. I now know more about the new Prophet than anyone else in Britain (or at least, I think I do), and I've been able to come to some very definite, on the whole favourable, conclusions about it.

The first of these conclusions is simply that the Prophet 2000 sounds wonderful. But that on its own isn't enough. We have to know why it sounds wonderful, because if we don't know that, we won't know whether our conclusions are based on scientific fact, or on the tricks our ears play on us when we've had one too many pints of the amber nectar.

Sample fidelity is a product of three factors: sample resolution (how many bits), sample rate (how often), and technical implementation (how good the design is).

A design like the Emulator II, with limited paper spec (8-bit, 28K), actually sounds better than many theoretically superior hardware systems, because of some design genius at the companding end of things. Meanwhile, the fidelity of the Synclavier's 16-bit, 50K sampling has never been in much doubt, because the spec-means you need to be a complete aardvark to go astray from such a high-performance starting point.

The Prophet 2000's analysis is 12-bit, its sample rate is selectable between 16K, 31K and 42K, and its technical implementation is superlative. The result? An instrument that sounds brighter than the Mirage, more immediate than the EII, and more transparent than the Kurzweil.

This isn't just a feeling I have after a couple of hours' listening across a crowded room. It's the result of sampling all sorts of things, from all sorts of sources, into the new Prophet and expecting the worst. But from Sony PCM F1 or Fairlight, Mirage or live musician, the sounds all went in and came back sounding near-as-damn-it identical - all with the minimum of fuss.

At a 16K sample rate, you can get away with bass drums and other low-pitched sounds; at 31K, 99% of all sounds are extremely faithful to the original; and for those tricky cymbals and ambient, low-level sounds, 42K does the trick. Thus you can choose between memory economy and ultimate fidelity at the flick of a switch, depending on the kind of sound you're sampling.

What I found most surprising was how simple and direct sampling could be on an instrument of this price. I managed to get a couple of hours in at a recording studio (thanks to Martyn and Greta at Paradise) to take advantage of mixing desk, outboard effects and the like with the idea of tweaking sounds- and found that this was almost unnecessary. No pre-emphasis (boosting the treble to prevent top-end loss resulting in duller sounds) was needed, and nor were any other of the other techniques which have become the sampler's stock-in-trade.

More specifically, one of the things that strikes you instantly about the 2000 is how immediate the attack to transient sounds is. This is something several excellent sampling systems have trouble with: drum sounds just do not have the same punch as the originals. Now, I've always ascribed this to programmable VCAs and VCFs not having a fast enough rise time, a suspicion that's given further credibility by the fact that drum machines- which have only static filters and no programmable VCAs - don't seem to suffer anything similar. Yet despite having both of these, the Prophet has a sharpness of attack more akin to that of the Emulator SP12 than that of a keyboard.

Emboldened by the lack of processing used in the studio, I took to sampling direct into the machine (a technique I'd previously advised people to avoid when sampling) either from CD or with a mic. Here I was greatly aided by the provision of both a mic/line level switch and an input level control. The LEDs on the front panel act as a VU level indicator: they hold peaks and display overloading clearly, though I found that, in any case, severe clipping had to be present before the sample quality deteriorated audibly.

The Parameter knob sets the threshold level when you're in Sample Record mode, and adjusting this is simplicity itself, as a flickering cross in the display shows you whenever the threshold has been exceeded. This makes setting the optimum threshold level much easier. The only thing you have to watch when switching to another parameter to adjust something else is that when you go back into Sample Record, the threshold is automatically set to the control's new level.

Having set a sampling rate, you allocate an amount of memory (up to 128K) to your sample. The Prophet actually has 256K of sample space, but this is stored in two separate blocks (Left and Right, or A and B) which cannot be combined, just like Upper and Lower on the Mirage.

The length of time you sample for is a product of the size of memory you assign and the sample rate. 128K gives you just over three seconds at 42K, just over four at 31K, and just over eight at 16K.

When you've set your level, your size and your threshold, you simply press Execute and wait for the next time the threshold level is crossed. As soon as it is, sampling begins. And when this happens, an 'S' appears on the LED display to let you know that the machine is engaged in the actual sampling process.

You can hear a sample on the keyboard as soon as it's been made, by moving to the Sample Number Parameter and pressing Execute. This overrides whatever maps and presets may be set up, and places the original pitch at Middle C. If there's a problem, you can go straight back into Sample Record for another go.

"Sampling - I got a couple of hours in at a recording studio to tweak samples with a desk and effects - and found it was almost unnecessary."

Surprisingly, the Prophet provides you with two loops for each sound: a Sustain Loop and a Release Loop. This means you can loop a different section of the sound for the release portion which, in turn, means you get more authentic copies of 'real' instruments.

This is the area where memory can be used most efficiently, provided you can find those elusive ideal loop points. More and more machines are providing looping aids these days, and here the 2000 again excels. There's more to it than the stepping-through of zero crossings, too. If you go past a good loop inadvertently, you can step back to it. The looped section sustains infinitely, so you don't need to keep a finger depressed on the keyboard, though it would be nice if you could use the keyboard to change the speed of playback so that you can check loops at different pitches to see if they are equally invisible to the ear. At the moment, you have to come out of Loop Edit mode to do this.

Once you have a result you're happy with as a starting point, you can immediately begin editing it (without all that tedious moving about between modules). You can alter the start and end points of sample playback, using the Parameter control to step through in blocks of 1K and the up/down switches to move from one zero crossing to the next. The latter feature is extremely useful, as beginning and ending at zero crossings removes any unwanted clicks or clunks. (All right, I'll explain. Zero Crossing is a sample in which there is no sound present during the sample time of about 30-40 microseconds.) Naturally, the ability to step through zero crossings is worth its weight in gold when you come to looping.

And if one sample with two loop points doesn't give you everything you need, you can combine samples in a variety of ways. You can mix two samples together by digital addition, using the Balance control to adjust the level between the pair. Or you can append one sample to another, at any point you mark with 'End' on the first sample and 'Start' on the second. Before or after either of these operations, you can reverse either the original samples or the result of your meddling, so overall, the range of options open to you is a pretty flexible one. So flexible, in fact, that repeated use of these features enables you to build up sound collages, and experiment with digital editing, in the same way as the pioneers of musique concrete used to do with analogue tape.

Once you've perfected your sound as far as the digital process will allow, you can get back to your analogue roots and do all the serious stuff with dynamic filters, envelopes, and the like, thanks to the 2000's analogue synth section.

But how is old-fashioned, analogue Prophet technology going to help digital sound better? Simple. Using an ADSR, for instance, you can cut out any undesired high-end problems such as noise in the original sample, or bring out interesting frequencies in the sample with resonance. The amplifier ADSR is equally useful, for smoothing out rough starts and finishes.

But both sets of controls really come into their own when you add a third ingredient: velocity-sensitivity. Now you can use the way you play the keyboard to alter the brightness (filter) and volume (amplifier) of your samples. Not convinced? Well, imagine sampling everything flat out, snare drums hit with huge vigour, pianos thumped with a vengeance, Gibsons distorting through Marshall stacks, and then introducing these subtle nuances of timbre and volume using gentle strokes on the keyboard.

What's more, and here we have another Sequential first, you can actually delay the point at which the sample readout starts with a soft key strike. In other words, if your cellist's bow bit into the string rather strongly as he attacked the note you sampled and you occasionally want something a little less forceful, you can program things so that a soft key-strike misses the front part and starts playing the smoother sustain section.

This vital technique for producing an authentic replica of an instrument over five octaves is so well-integrated into the 2000's architecture, you don't even need to select a special option to employ it.

The sample memory of each side of the keyboard can be split into as many as eight separate blocks, and these are then mapped onto the keyboard at will to create an 'instrument' (a piano or a drum kit, say) over more than the 2½-octaves each sample can be played over. You can make global parameter changes for each map, so that having adjusted each sample to match them up, you can mess about with them all at once if necessary. Having built up your maps, you can then combine two of them together into a preset.

When you load a factory disk into the Prophet 2000, you use the presets to access the sounds. The 12 presets can be used to make different arrangements of the same sounds, or each one can access a different pair of samples to give complete sound changes.

It's within the preset area that all the clever things like keyboard splitting and layering, velocity switches, crossfades and positioned merges are set up. Each preset draws upon two maps to create its overall set-up, so that only one merge over the five octaves is possible (not as useful as the EII, where any number can be set up), but this aside, there are virtually no limits as to what you can do: drum kit one side, flutes the other; a piano doubled with strings; marimba on hard strikes, glockenspiel on soft. If you can squeeze it into 256K of sample memory, chances are it's possible. And all these goodies are accessible instantaneously in real time, something that helps get round the fact that load times can be as long as 20 seconds (the 2000 has over twice as much memory as the Mirage) by letting you keep different sounds for the same song available in memory at the same time, all loaded from one disk.

Luckily, Sequential have realised that the floppy disk is not the most reliable of storage media, for the 2000 has its complete operating system on ROM. In other words its brain is internal and inseparable (except to an engineer with a screwdriver and an EPROM remover) from its body, a state of affairs which I find very reassuring. Even if you lose all your disks, it won't stop you sampling new sounds.

If you turn on your 2000 without a disk in the drive, it downloads from ROM a series of waveforms into the sample memory area. Then, using the analogue parameters, 12 presets are made up using these waveforms, which are made by a mixture of additive and subtractive synthesis. At this point, it's worth dispelling the rumour that the 2000 'comes with Prophet sounds built in', which implies that the old analogue oscillators that gave the fat, beefy synth sounds of yesteryear are present in the sampler of today. True, the 2000 still uses the old faithful Curtis chips for filter and amplifier, but the basic waveforms that make the new Prophet's sounds are digitally generated, digitally encoded in ROM, and then read into the D-to-A converters just like the samples whose place they are occupying.

Listening to these sounds, this is fairly clear straight away. They have more in common with the clear, bell-like sounds of the current Yamahas, Korgs and Casios than the great American analogue synths of the past. These combination analogue/digital sounds provide usable alternatives to sampling, and would certainly get you by in an emergency. There are organ sounds, bell sounds, plucky synth sounds, and other typically digital voices. You can edit the sounds and store your own versions of them on disk, but more significant is the possibility of using them alongside or in digital combination with samples.

However, I can't help feeling that if any waveforms are going to be permanently implanted in ROM, there are more commercially-popular choices. Maybe the ROM available in the 2000 is insufficient, but I'd have thought a built-in piano or strings sound would have been more useful.

In many ways, you get the feeling that the way the Prophet 2000 combines synthesised and sampled voices is only the tip of the iceberg, rather than the ultimate in sound manipulation for years to come.

"Synthesising - I'd have thought some built-in piano or strings sounds would have been better than the synth presets resident in the 2000."

The third disk is more promising, with an excellent acoustic guitar (steel strings sparkling beautifully). Coupled with a useful organ sound, this is the best of the three disks you get with the 2000, but, just to prove that every silver lining has a cloud, there's also an utterly unusable bass guitar sample.

Played within certain regions, the piano sounds excellent: rich and growling down the bottom, clear and sparkling at the top. Trouble is, the sound changes in character spasmodically several times in between. So much so that around the fourth C up, there's what could almost be described as a wah-wah effect. As they used to say on your School Report — 'needs work'.

The strings sound is rather thin and unsatisfying, and the strings/brass disk as a whole is irritatingly set up and leaves areas of the keyboard unassigned.

But if the ROM-based synth sounds do little to make a strong initial impression of what the Prophet 2000 is capable of, the factory sample disks do even less. For while the sound quality of individual samples is often extremely high, they are patchily assembled into presets.

I strongly suspect that by the time the second wave of 2000s hits Europe, the problems noted here will have disappeared. Not that you should care, anyway. What matters is that the new Prophet is capable of storing some tremendous sound samples, if only you've got the courage to leave the factory presets to one side and do some sampling of your own. If I had my way, all factory sounds would be withdrawn from instruments a week after their purchase - then we'd find out who the real programmers are.

Besides having a full compliment of the usual MIDI specifications, the Prophet 2000 has several major innovations based on the universal interface standard. Passing quickly over the standard Omni and Poly modes (though there's an expansion on the latter that allows you to assign a different MIDI channel to the left and right memories), let's get onto the meaty stuff.

The first innovation concerns MIDI mono mode. In the original MIDI spec, mono mode was included as an option to allow each voice of a synth to be addressed separately by an external controller. On the 2000, this would mean eight channels accessing the eight available voices. However, Sequential have taken this a stage further by enabling the 16 available sample locations to be accessed on 16 separate MIDI channels. This means that, using most MIDI sequencers, you can sequence 16 different sounds simultaneously, provided only eight are sounding at any one time. Neat, huh? You should hear it. And don't be misled by the word 'mono' in this context.

It refers to the MIDI mode, not a lack of polyphony. Provided you don't exceed eight notes at any one time, you can have eight notes on each track, so each track can be fully polyphonic to the hardware limit of the 2000. In reality, you're unlikely to use this to its full potential, as if you're using a few drum sounds, bass and lead lines, you'll only need to hear some of those sounds monophonically anyway.

Then we come to expansion modes, a concept unique to the Prophet 2000. Each of the three modes (omni, poly and mono) can be used in an expanded format. What this mode does is to not transmit anything over MIDI until all eight voices are being used. So, instead of stealing voices to play new notes as in the normal playing mode, any notes that exceed the instrument's eight-voice capacity are transmitted via the MIDI Out socket. This means that a second (or third, or fourth) 2000 connected and loaded with the same disk can provide these extra notes automatically. Just think of the advantages. 16-note (or 24-note, or 32-note) piano chords, splits and doubles that don't deprive you of polyphony on each sound, and best of all, in mono mode, the ability to play 'live' all the separate samples polyphonically, which you can put down track by track in the studio.

At the June NAMM show in New Orleans, the American MMA (MIDI Manufacturers' Association) decided on a data format for sample transmission via MIDI. The 2000 is the first synth which implements this format, allowing you to send a recorded sample from one 2000 to another down the MIDI cable. Not terribly useful, as you can always just load the same disk into both. But think of the other implications: with suitable software (currently in preparation and with us in the New Year), you'll be able to send a sample to a computer to edit or store it, and when E-mu and Ensoniq release software updates to include this data format, you'll be able to shunt samples around between machines without all that tedious mucking about with resampling. Of course, eight-bit machines will have to ignore the extra four bits the 12-bit 2000 has, and similarly, the 2000 won't have the last four bits available if the sample has come from an eight-bit machine. But get yourself a suitable modem, and you'll be able to send samples down the phone to your mates in California, Tokyo or New South Wales. Now there's what I call global sampling.

The only possible problem with all this is that sound samples use up a lot of MIDI data, so transferring a sound over MIDI can be rather time-consuming. But Sequential have thought of even this, as the 2000 can be switched to operate on twice the normal MIDI transmission rate. For the time being, this facility is only usable in conjunction with another Prophet 2000 switched to the faster rate, but as Sequential say in the manual: 'we fully expect future models from other manufacturers to have this double speed ability'. If double-speed still isn't fast enough for you, the 2000 can also be switched by remote command from a computer, to transmit and receive at three or even four times the standard MIDI rate. That should set the cables smoking.

All these features enhance the flexibility and longevity of the 2000, which will still be holding meaningful conversations in years to come when other 1985 MIDI specs will seem like caveman's grunts rather than philosophical treatises.

Do I have any grumbles? Well, yes I do. The inclusion of an arpeggiator, however intelligent, does seem backward-looking, and contrasts with the forward-looking nature of the rest of the instrument. I know there are those of you out there who love them dearly, and you won't be disappointed in this one: it's as flexible as they come. But I can't help feeling that a sequencer, however rudimentary, would have been more in keeping with the times. True, there's an Assign mode that allows you to build up sequence-like strings of notes, but as there's no way to save these, the facility is of limited use unless you fancy the idea of programming your sequences in front of your audience.

Next, and more crucially in view of the flexibility of the 16 sample locations, the dynamic allocation of the eight voices, and the different analogue parameters which can be assigned to different maps, there is only one LFO. Effectively, this means that in multi-timbral applications of the 2000, only one sound can use vibrato or tremolo effects unless all sounds are to modulate at the same rate. In view of the fact that everyone's LFOs are software-generated these days, this amounts to criminal negligence. Let's hope the situation is remedied soon.

The last criticism is a purely subjective one. The entirely metal case, complete with DX-inspired membrane switches and pastel shades, is hideous. The E&MM shutter-man, in mid-photograph, was heard to liken its front panel, with its funny triangles and mis-matched colour scheme, to a One Two Testing front cover, and while I wouldn't go that far myself, I can see what he means.

Myself, I thought the old Prophets looked classy, so you can be sure that the minute mine arrives (I got my order in early), I'll be sawing up one of my parents' best coffee tables to make the traditional wooden Prophet end cheeks, which I shall then glue onto the 2000.

Well, that marks the end of my complaints, pitifully few in contrast to my overall wholehearted approval of the Sequential newcomer.

The Prophet 2000 is the most faithful sampling keyboard yet available this side of the Synclavier. Stick the sounds in, and back they come accurately and instantly. The combination of analogue and digital editing facilities makes them more flexible than those of any other machine. As well as rescuing many a bad sample, editing sounds Prophet-style can render good samples more expressive and inventive.

An internal operating system, a clear front panel layout, and an unrivalled MIDI specification avoid the principle drawbacks of the Mirage. My advice? Pay the extra money, throw away the factory disks, and start your own sample library. You won't regret it.