In the rush to give away a Prophet 2000 Sampling Keyboard in our recent competition, it quite slipped our minds to actually review the machine. However, the release of a 19-inch rack mounting version, the 2002, plus a whole host of updates and support options gives Paul Wiffen the perfect excuse to make up for our omission and bring you the latest on the development of the Sequential sampling system.

As a programmer and journalist, a chap often gets to see new products ahead of time. This was the case in September of last year when at the Milan Trade Show (fortunately arranged by those terribly nice Italian chappies to coincide with my holiday on Lake Como just up the road), I first laid eyes, and more satisfyingly, ears on the Prophet 2000 sampling keyboard. Despite the fact that it was still in prototype form, I was somewhat impressed by the sound quality. At that stage I had been working as an Emulator II programmer for just over a year and whilst I still maintain a great affection and admiration for that instrument, it was clear to me that the 12-bit format and faster sampling rate of the Sequential machine represented a marked improvement in fidelity which, coupled with the unprecedented drop in price from ten to two thousand pounds for a sampler of this quality, made it incredible value for money.

I made it my business to acquire one as soon as possible. From subsequent use in studios I have found the Prophet sampler to be second to none in terms of accuracy and flexibility. It has the fidelity of an AMS with the analogue processing capability of the Emulator. It suffers less from aliasing than the Synclavier when you replay the sample lower than the original pitch and yet any aliasing that starts to creep in can be quickly and easily dealt with using keyboard-tracking filters which the Synclavier system doesn't have. It sounds brighter than a Kurzweil, cleaner than a PPG and allows faster attack times than the Emulator, yet costs a fraction of any of them.

But I knew it couldn't last.

Someone was bound to improve on the 2000 spec, or make something compatible for a much cheaper price. This year, as I sat on the plane going over to the American Trade Show, I planned how I would sell off the superceded Prophet 2000 via a classified ad as soon as I returned, having made my choice of the new samplers which I was about to see at the show.

First I saw the Korg DSS-1. Sounded quite nice, but only 128K of memory (half that of the 2000). Next, the Roland stand. The S-10 (the small one) suffered from the same problem as the Korg, only four seconds of sample memory. Both only sample at 31.25kHz (the middle rate on the Prophet) as does the larger Roland, the S-50. However, this model would have double the 2000's memory, 512K, giving 17 seconds of sampling time. At a price though, of well over three thousand pounds.

The Akai S900 (also with 512K) looked more reasonable at less than two grand. What's more it could sample at 40kHz - almost as good quality as the 2000's best sample rate of 42kHz. This looks like being the best of the rest but it won't be available till May.

So, these seemed to be the sum total of my options. I knew I wanted a 512K machine, but which? The one with 17 seconds of reasonable quality (Roland S-50) or the one with 12 seconds of high quality (Akai S900)? There I was still on the horns of this dilemma as I walked onto the Sequential stand where I found I didn't have to choose between these alternatives. For the ridiculously cheap price of £325, Sequential had a 2000 memory expansion to 512K which gives both options.

However, when I returned to England, I did sell my Prophet 2000. What I replaced it with, though, was the new Prophet 2002 (exactly the same internally as the 2000 but in keyboardless 19-inch rack format) with the expanded memory, giving me exactly the same memory capacity now as Roland and Akai will be offering come May/June, but with the choice between 31.25 and 42kHz sample rates. The best of both worlds!

My reasons for choosing the rack-mount 2002 were as follows:

1. It weighs a lot less than the keyboard version.

2. The colours on the front panel clash less than on the 2000 and it looks neat in my rack between the Roland MKS-80 Super Jupiter and the Yamaha TX816, giving me the best of analogue and digital synthesis and sampling all in one box.

3. In common with the MKS-80 and the TX816, both the 2000 and the 2002 can respond to MIDI pressure data. But the 2000 keyboard doesn't generate aftertouch information, so I had been playing the 2000 from my Prophet T8 anyway (you could use your DX7 - everyone but me seems to have one!). Also both respond over seven octaves via MIDI.

4. The real switches on the 2002 respond more positively than the fake membrane switches of the 2000. I had started to become irritated by the occasional 'key bounce' when programming the 2000.

5. The sample input, level control and mic/line switch are located on the front of the rack-mount unit where they are easy to operate, unlike the 2000 keyboard where they are hidden away on the back.

But all these, for me, are insignificant compared to the biggest advantage the 2002 had over the Roland and Akai; all the samples I had already taken on the Prophet 2000 could be instantly loaded into the 2002 as they are internally identical. So let us examine those very things which the 2000 and 2002 have in common.

SHARED SPEC

Sample resolution of both the Prophet 2000 and 2002 is 12-bit, a step up from the 8-bit systems of E-mu and Ensoniq and the 10-bit of the Kurzweil. Sample rates available are 16, 31.25 or 42kHz. As we have already seen, 31.25 gives a good general purpose sample quality, with the extra fidelity of 42kHz available for those tricky 'top-heavy' sounds. Different sample rates can be mixed on the same disk, so each sound can be sampled at the most suitable rate dependant on either economy or fidelity. The Prophets come with 256K of sample memory giving 16, 8 and 6 seconds of sample time at 16, 31.25 and 42kHz respectively. With the expansion kit (Model 877) fitted, the memory is doubled to 512K giving 32, 16 and 12 seconds at the same rates.

This memory can be split between up to 16 samples which can be stored in the Prophets at the same time. These can be 'mapped' onto the keyboard, or more instantly, controlled independently via MIDI's Mono Mode (Mode 4) with each sample playable over its full range on a separate MIDI channel. This is my favourite way of using the Prophets, for reasons which will become clear later.

SAMPLING

This is simplicity itself. In Sample Record mode, the LEDs on the front panel show the level of the incoming signal. This can be switched between mic and line levels and adjusted with the input level control. Overloading is clearly shown on the vertical LEDs, whilst lighting all the horizontal LEDs gives you the optimum signal-to-noise ratio for sampling.

Having set a sample rate and size (the interaction of which gives you the sample length), sampling can be triggered manually or by means of a threshold. This is set in Sample Record mode by the Parameter Value knob, a cross showing when the incoming sample level exceeds the threshold.

EDITING & LOOPING

Once a sample has been made it can be placed on Middle C quickly by using the Map Override mode. Tune Sample gives both coarse (Parameter knob) and fine (Up and Down switches) tuning, with an A (440Hz) reference available in true Prophet tradition. The Start and End points of the sample can be altered in 1K jumps (the Parameter knob again) or in smaller jumps made by moving between one zero crossing and the next (via the Up and Down switches). The latter is extremely useful for fine editing, when removing unwanted clicks at the beginning and end.

Two loops are available for each sample on the Prophet. The first, the standard Sustain Loop, is used to keep a sample sounding indefinitely (or at least as long as the key is held down), whilst the innovative Release Loop can be used to keep the same or a different section of the sample cycling whilst the Release portion of the envelopes are taking effect (once the key has been released). The 2000/2 is the only system with this feature.

Looping is much easier on the Prophets thanks to the Up and Down switches which automatically find zero crossings for you. 'Zero crossings' occur where the sample momentarily registers no sound (for 1/42,000th of a second, say, when sampling at a 42kHz rate) and looping between these points in a sound tends to give less trouble with clicking as the loop goes round. Most sounds can be looped successfully using these zero crossings, but those of you who want to 'loop the unloopable sample' will be interested in the Sound Designer 2000 software which we will look at later on.

Samples can also be spliced together ie. digitally combined (mixed at different levels) to allow more effects to be created.

ANALOGUE PARAMETERS

Once you have finished with the digital manipulation of your sample you haven't run out of things to do. You have a full VCF and VCA with velocity control available to further process your sample. The Attack, Decay, Sustain, Release and Alternate Release (with pedal down) can be altered for both brightness and loudness and, as mentioned earlier, the Keyboard Tracking can be used in conjunction with the Cut-Off Frequency to overcome aliasing problems at pitches over an octave below the sampled frequency. Velocity from keyboard performance can control Attack and Release times and the peak of the Loudness and Brightness envelopes. In another innovative stroke, velocity can control the Sample Start Point. For example, a soft key strike could be set to omit the very front of the sample, useful for avoiding an obtrusive toot or scrape on gently-struck brass or string lines, but leaving the more punctuated beginning on notes played more forcefully.

MAPPING

When you have recorded as many samples as you need,you can begin to position them across the keyboard using the Prophet's mapping system. This is the only area of the machine which can be a bit confusing. Nothing, however, that a couple of read-throughs of the mapping section in the user manual won't tell you. Still, I know how painful that process is to most musicians ("when all else fails, read the manual!"), so here's a quick synopsis.

Each complete assignment of the keyboard (called a Preset - there are twelve available) can use two 'maps' in combination to achieve the various sample layering, splitting and crossfading options. But before we get into such advanced uses, we need to be able to assign sets of multi-samples which we want to use together. This constitutes a 'map', and it is useful to think of it as an instrument. For example, the first four samples assigned we could call Hard Piano Strikes or Tibetan Nose Flute. We could then create another map, say Soft Piano Strikes or Polynesian Ear Trumpet, and then velocity cross-fade between the first two, or layer the second two.

Creating a map merely requires keeping your wits about you (and a bit of time). Dial up the lowest Sound Number you want to assign, switch to Build Keyboard Map mode and use the Parameter knob to set the octave (1-6) in which you want to place it (Step 1). Then step up/down to the exact key you want the original pitch assigned to (Step 2). The display tells you exactly where you are ( C4 or +F1 - where '+' means 'sharp'). Now play the highest note you want to sound this sample and then press Execute (Step 3). Not so difficult, huh? Now when you go back to the Sound Number, you will find that this sample plays from the bottom of the keyboard up to the note you specified. Then step up to the next sample number you want, go back to Keyboard Map and repeat the original pitch and top key assignment procedure (Steps 1, 2 and 3). When you go back to Sound Number now, you will find that this second sample carries on from where the first one stops, up to the note you have just specified. Repeat Steps 1, 2 and 3 for each sample you wish to assign in rising order of pitch.

Here are a few things to bear in mind when mapping:

1. Sound Numbers 1-8 can only be assigned to Map Numbers 1-8. Similarly Sound Numbers 9-16 can only be assigned to Maps 9-G (the only bit of hexadecimal code you will see on the 2000/2, unlike the Mirage which uses hex half the time!). Make a habit of going from Sound Number to Build Keyboard Map via Map Number to check compatibility - it's on your way! Otherwise you will keep seeing 'nA' (Not Assignable) in the display when you get to Build Keyboard Map.

2. If you are getting an unwanted Sound Number you can get rid of it by turning the Parameter knob all the way to the right (display shows 'CL') and then back till 'OF' appears, when you are in Build Keyboard Map mode. But you can avoid this problem in the first place by using the Clear function before you start assigning samples.

3. Plan out your map on (a photocopy of) the chart Sequential provide in the manual before you start. It will make life easier - that's why it's provided!

4. Save everything ('S' in display then Execute) to disk regularly. Then if there is a power cut - or the dog pulls the mains lead out - all of your work won't have been lost.

KEYBOARD MODES

When you have made up your maps, you can begin to combine them for exciting performance effects. These are the available modes:

Left Map Only - only the map number on the left when you call up Select Maps will sound.

Right Map Only - only the map on the right when you call up Select Maps will sound.

Split - the map number on the left plays on the lower keyboard, the one on the right on the upper keyboard. Split Point can be used to change the note where they cross over.

Layer - both maps sound across the whole keyboard (if assigned), like in conventional doubling on a synth. Use the Balance knob to adjust relative levels.

Velocity Switch - both maps are available across the keyboard (if assigned). A soft key strike plays the left map, a hard key strike plays the right map. Use Velocity Threshold to alter the point at which they switch to suit your playing style.

Velocity Cross-fade - as above, but instead of switching over at a fixed velocity, a medium key strike plays both sounds at half volume. Harder strikes give progressively more of the right map, softer strikes give more of the left map.

Positional Cross-fade - the lowest note plays just the left map. As you progress up the keyboard the right map is increased in level and the left map is decreased till at the top you hear the right map only. Great for turning cymbals into flutes or pianos into trumpets as you move up the keyboard. Not so good for smooth transitions between two multi-samples of the same instrument. If anyone at Sequential reads this, can I suggest a possible Cross-fade Merge mode to achieve this?

Merge - although this is the first mode the Prophets offer, I have left it till last as it is the most complex. It takes the lowest sample from the left map, then the lowest from the right, then the next lowest from the left, then the next lowest from the right and so on. The left map has priority so if you have the maps identical then you will not hear the right map. But by interleaving them you can place 16 samples across the keyboard. This is extremely useful for mapping out drum samples to be triggered from a MIDI drum machine or sequencer.

In defence of Sequential, it must be said that mapping is easier than on the Mirage as notes are referred to by name not number. And to those who complain that mapping is not as easy as on the Emulator II, there is a very good reason for this. Visual displays like that on the EII cost money both in hardware and in software. That's partly why an Emulator II costs seven grand plus VAT, when the Prophet gives better sound fidelity for two grand inc VAT. You cut your coat according to your cloth...

OUTPUTS & MIDI

Another area where people have criticised Sequential's 2000 is in the provision of only two audio outputs: left and right. Again, the general public has no idea how much extra outputs would put on the price were they to be added. If eight outputs is that important to you then for the time being you must expect to pay EII money. But before you buy an Emulator II, think about getting an expanded memory Prophet 2000 and three expanded 2002s. They'll cost you roughly the same (about eight thousand pounds) and both will give you eight outputs, but with the Sequential set-up you will have a 32-voice system with superior quality sampling. Sounds like a bargain to me.

However, for those of you with more modest budgets like myself, clever use of MIDI can get around the lack of outputs. Via Mono Mode (Mode 4 as Sequential call it) each sample can be accessed on a different MIDI channel so you can externally sequence each one of the 16 samples. Then for signal processing whilst recording, just sync your sequencer to tape and play back each track separately - as you would probably do anyway.

The ability to hold 16 samples in the machine becomes even more exciting with the memory expansion facility. Now each sample can be twice as long and, of course, the extra memory gives you more space to move samples about internally and swap them to get on the right MIDI channels.

SOUND DESIGNER

Another splendid prospect for Sequential sampling was also announced recently. The Digidesign 'Sound Designer' software (Apple Macintosh-based), which I fell in love with when I first saw it used in conjunction with the Emulator II last summer, is now available for the Prophet 2000 and at half the price - $495 instead of $995. It also uses any Mac-to-MIDI interface such as the MIDI Conductor at $89 which you can also use with a Mac MIDI sequencer package. Argent's Keyboards in London already have the 2000 Visual Editing package on demonstration and hope to receive final versions for sale at the beginning of April. The UK price (dollar permitting) will be £395 for the Sound Designer software and £69 for the interface.

In addition to the splendid looping, editing and digital synthesis features of the existing Emulator II package, the Sound Designer 2000 software has several interesting extras. An on-screen 'MIDI keyboard' allows you to play a 2002 module using the Mac Mouse, and there are several automatic play functions. 'Pattern' plays all seven octaves from low to high so you can hear what's assigned where on the keyboard. A short sequence can also be recorded to check how editing affects playback. For those who still find mapping difficult to grasp after my explanation, Sound Designer shows it graphically. In addition, Sound Designer files (ie. samples) created from either the Emulator II or Mirage versions (also available shortly) can be loaded via the Mac into the Prophet 2000 - instant sample compatibility!

There is no time now to cover the whole specification of the Sound Designer which really merits a review all to itself, but suffice it to say that it is the most complete sample editing package to date and it is constantly being updated. In fact, I heard the other day that Roland were thinking of getting Digidesign to do a version for their new S-50 Sampler which would come with the machine when it's available this summer.

For my money anyway, the Sound Designer is the best package around and that coupled with all the splendid sequencing and patch librarian software you can buy for the Macintosh make it the perfect compliment for the Prophet 2000/2.

CONCLUSION

Overall, the impression one gets from the Prophet 2000/2 (taking memory expansion and Sound Designer into account) is of an interactive system which gives greater MIDI-controlled flexibility and sample fidelity than was previously available at any price. In the four short months that the Prophet has been on sale, the library of sounds has grown fast. Already there is the memory expansion to take sample times up to the same level promised by the competition for later in the year and the new Strings, Brass and Piano disks which use the expanded memory are superb.

With a good sequencer (either on the Macintosh or a dedicated unit - I suggest the new Roland MC-500 when it becomes available), both Prophets outperform specifications previously only offered by Fairlights and Emulators, and at a fraction of the cost. And with the Prophet VS synth coming along soon to handle both analogue and digital sounds, my money's on Sequential in '86. And that's no glib journalist's phrase either. This is actually what I'm spending my money on!

Latest Sequential prices inc VAT:
Prophet 2000 - £2199
Prophet 2002 - £1899
512K memory expansion - £325 plus fitting (30 mins)
Digidesign Sound Designer 2000 - £395 plus £69 for interface
Prophet VS-£1899

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