THIS ISSUE'S episode finds me in Grand Rapids, Michigan, writing this review while traipsing through the American Mid West in search of cutting-edge technologies for "The Micro Live" programme (weekly this autumn on BBC2 — unabashed, unrepentant plug). My head is full of 100-gigabyte-to-the-square-centimetre, laser-written, mass-memory disks made of bacterially-derived rhodopsin, and robots designed to clean up the sludgy radioactive hell inside Three Mile Island, and the esoteric concerns of something Artificial Intelligence researchers call "fuzzy logic". With all that bouncing off the walls, you wouldn't think I'd be inclined to include a £1695 keyboard instrument in with the edge-cutters.

But I am. It all depends on the edge being cut.

Meet the Ensoniq Mirage, inexpensive digital sampler/synth. Essentially, the Mirage is a souped-up, MIDIfied, modernised take on the structural concept of the Emulator I, selling for a quarter of the price and weighing in at under a third the poundage. Proof positive of the wonders of applied VLSI (Very Large Scale Integration — the art of taking circuitry that is already small and making it positively microscopic, so that one chip can replace dozens). The folks at Ensoniq have laboured long and hard to create something they call the "Q Chip" which has all the basics of sampling on a single-layered flake of silicon. Add on a five-octave velocity-sensitive keyboard, a two-character alphanumeric display, a couple of coprocessors (8-bit Rockwell 6500 and 16-bit Motorola 68B09E), linking circuitry and output electronics as required, a lot of intense software writing, and you have a Mirage.

You also have a tremendous gamble — can you sell enough £1695 keyboards to pay back the million-plus dollars you spent to develop the Q Chip in the first place? It's exactly the opposite marketing tack of, say, Kurzweil Music Systems, which is trying to make back its massive R&D cost by selling a few instruments at a high unit price. Ensoniq would prefer to be mentioned in the same breath, a couple of years from now, with the likes of Roland, Korg, and Yamaha. They want to penetrate the mass market, not the high end.

So far, the gamble appears to be paying off. Since the Mirage was officially introduced at the NAMM show in February, the orders have far outstripped Ensoniq's manufacturing capacity. The company is catching up (by licensing out manufacture of the European version, among other things), but only by running as hard as they can. Stock is so sparse in the States, in fact, that their best efforts were unable to break loose a machine for review, forcing me to get my hands-on time by hanging around Manny's Music in New York for hours on end, fiddling with the demo unit. Credit where credit is due — I am grateful to synth whiz Rick Stevenson, at Manny's, for making it all work out.

Pros and cons, as I encountered them, in a moment. But first, the matter of pedigree. The Mirage didn't just pop out of nowhere.

Ensoniq was started by three people who had never worked in the musical instruments industry before: Bob Yannes, Al Charpentier, and Bruce Crockett. They came together in the computer industry, actually. Charpentier and Yannes designed the Commodore 64 and VIC-20 home computers, and Crockett was Commodore's Vice-President in charge of manufacturing. Ensoniq's more-for-less-money philosophy comes straight out of its Commodore roots (as does a stripped-down and basic approach to hardware). It was Yannes and Charpentier who created Commodore's three-voice SID synthesiser chip; when they decided to break off and start their own company, it seemed eminently logical to use their computer-design experience to tackle sampling.

In the words of Robin Weber, representing Ensoniq's marketing side: "Sampling was the perfect choice for us because, until we started working on this chip, you could only get sampling for seven to eight thousand dollars or more. It was a technology that was gaining considerable acceptance in the studio and in performance, but it was still way out of reach of the average musician. And if we'd just tried to develop a standard digital synth, we'd have had to go head-to-head with companies that were already well-positioned in our targeted price range."

Staying in that price range meant keeping component costs down. VLSI helps. So does using cheaper components, and fewer of them. Front panel control of nearly a hundred different programming parameters is handled by a volume slider, a two-character amber display, and 24 small buttons in sections labelled CONTROL, SELECT, SEQ and SAMPLE. The back panel has a similar simplicity, with connections for a single footswitch, sync, audio out, audio in (software selects whether the jack is line or mic level), a computer/cartridge expansion port, MIDI IN, and another MIDI plug that selects between OUT and THROUGH.

It's at this level that I have actual complaints about the Mirage — and even as I speak to them, I hear a voice from somewhere else in my head saying, "Yeah, but for £1695 you've got to expect some compromises." But the lack of multiple outputs is worrying. Having a single audio out is terribly limiting on a sampling instrument, especially on one that is capable of some fairly fancy multi-sample, multi-timbral games. These cry for separate outputs and signal-processing and, on the Mirage, you don't have the option.

And how about that selectable MIDI OUT/THROUGH? Would it really cost all that much more to add a DIN plug and a little more circuitry?

Worst of the lot, though, is the keyboard. It's cheap. It feels like it. The electronics in it seem to be fine — good contacts, clean velocity sensitivity, fair durability — but its feel is not destined to give you Happy Hands. Do yourself a favour. Do NOT test play a Mirage first time out with the volume down or off. Otherwise, you'll focus so much on the feel of the keyboard, you won't really find out if the sound makes up for it. Because it is the sound that counts at £1695. If that's there, none of the objections I've just raised mean very much — except for the one about multiple outputs, of course, since the better the sound, the more painful that lack becomes.

The sound is most definitely there.

Not in a class with the Kurzweil 250 and Emulator II, to be sure, but very solid. As good or better than an Emulator I, certainly, the Q Chip is a winner. That said, time to move past first impressions and on to systems architecture.

The operating system doesn't live inside the Mirage. It's in software, on a hard-cased 3½ in floppy disk that fits neatly into the Mirage's discretely-placed disk drive. You load it in every time you turn the instrument on. Using this approach is a Good Thing, because it lets Ensoniq do a considerable amount of upgrading through improved software. And the hard-cased disks are durable and easy to carry around. You also use these disks to store your own samples and sequences. As with the Emulator I, the disks have to be specially formatted, which prepares them for storage. Unlike that instrument, however, you can't get software that will let you format your own. You have to buy them, already formatted, from an Ensoniq dealer.

Having turned on and loaded up, you face the problem of understanding how to use the instrument. I'm going to gloss over all the basic operations. Trust me: they are there and they work, and the envelope and filter controls turn out to be remarkably useful — something I never thought I'd say about a sampling-based instrument. You will have a good time with it, and the way you change and adjust parameters is easy to learn from the manual. On those points the manual is very clear.

Where the manual is not clear is in the matter of sampling itself and, more specifically, in how sampling memory is arranged, without that knowledge, you will be severely hampered in your attempts to really make the Mirage perform at its optimum levels. This lack of information is annoying, particularly when it's readily available in the Ensoniq "Advanced Sampler's Guide". Only thing is, to get it you have to buy the MASOS — Mirage Advanced Sampling Operating System — disk, which is an added expense. Typical. Or else, of course, you can read it here in a few seconds' time. I'm not above telling.

Actually, I heartily commend the "Advanced Sampler's Guide" to your attention, whether you own a Mirage or not. It's written by Bill Mauchly, one of Ensoniq's software people and son of John Mauchly, the original "father of the modern computer". Bill knows his stuff, and has written the most straightforward and useful text on sampling and its attendant difficulties I have ever seen. Full of useful tips, too, useful for everybody from Synclavier-owners on down.

Groundwork

The Mirage has eight voices. Each voice is made up of two digital "oscillators" (really the playback of the sampled waveform), one LFO, a mixer and DCA, a VCF, and envelope generators that route to the DCA and VCF. When a voice plays, you will either hear one of those "oscillators", both of them, or some mix of both, determined through keyboard velocity or the mod wheel. You can also set standard mix levels in software.

The question is, how do you play games with the samples? And the answer is, you learn how memory is allocated.

There are two big chunks of memory, UPPER and LOWER. Each is 64k and can be further divided into eight WAVESAMPLES. Total: 16, any one of which can spread over as much of the keyboard as you choose, and any one of which can occupy as much of the memory as is available (ie, you can have two 64k wavesamples, or four 32k wavesamples, or three that are 30k and three that are 10k and one that takes up the 8k which is left — up to you). That UPPER/LOWER thing is a little bit of a misnomer in that it leads you to think in terms of halves of the keyboard. Not so. Fact is, these 16 possible wavesamples, each a discrete sound, are best visualised as 16 strings that start at the left side of the keyboard and run as far to the right as you choose... and each string obscures the ones behind it, preventing them from being heard. The trick is in the number of the wavesample and the high note you choose for it in software. Treating it this way allows you to make a single "instrument", like a piano, out of 16 different wavesamples (just keep setting higher and higher end notes as you progress from wavesample 1 to wavesample 16), or carefully construct multitimbral keyboards. You can also set up alternating wavesamples so that sections of the keyboard contain two samples, as mentioned, before, that can be mixed in various ways.

When you dig into sample-making and editing on the Mirage, you also have to dig into finer divisions of memory called PAGES and (gosh, how confusing) SAMPLES. Each of the two sections of memory, higher and lower, has 256 pages, and each page has 256 samples. These are all three-digit numbers, and the cost-conscious Mirage has a two-digit display. So prepare yourself to start working in hexadecimal. This isn't so bad; partially because you won't bother with anything outside the instrument's standard defaults unless you're dedicated, and partially because the Advanced Sampler's Guide has a pack of useful conversion tables in the back.

Now let's talk sampling rates, particularly since the Mirage doesn't. Instead, it deals in sampling TIMES, and derives the rate from the time you choose. The default time is 2.2 seconds per keyboard half, which is a sample rate of 33kHz. That's the fastest the standalone Mirage can get, and you'll get a bandwidth of (theoretically) 16-plus kilohertz out of it. In practice, the noise filtering — both automatic and what you will choose to add yourself on some sounds — reduces bandwidth well below that. And then you'll lower it even more by extending the sample time, should you choose to do so. At its maximum time setting, you are going to be down in the 4-5k bandwidth.

Sampling rates interact with wavesamples in the following way: that 2.2 seconds per keyboard-half mentioned above, at maximum rate, means that if you want eight wavesamples in that chunk of memory, they'll all average a shade over a quarter of a second, tops. To do well with that, you are going to have to get real good at looping...

And since better looping and the capacity to do reversals, crossfades, ramp scaling, waveform additions, inversions, and a lot of other data manipulation goodies are what the MASOS software is all about, I guess I'll just leave it at a heavy recommendation that, when you buy the inexpensive Mirage, you shell out some of what you saved to grab that disk and ever-so-valuable manual.

What am I leaving out? Features, features, features... there's a simple sound-on-sound sequencer, with 333-note capacity. Be warned that while it will record pitchbends and modulation, they are global. That is, bend the pitch of one note on one track, and you've just bent every other note you're hearing, even if they were recorded on earlier passes. You can store sequences to disk; each formatted disk makes room for eight.

And then there's expandability. Time to cover that in a bit more detail. MASOS software I've already mentioned, but I didn't cover the fact that there's an Apple II interface over the MIDI so that you can do all the loop editing and reversals and such visually, as well as control all the other Ensoniq parameters for vastly improved editing performance. There will also be expansion cartridges out by the time this article hits the streets (or very shortly thereafter, I am assured) which plug into the port in the back and allow you either to expand the sequencer memory to 1300 notes, or sample at 50k as a maximum rate! (Of course, at that rate, you've got 1.3 seconds of memory for each keyboard half, which isn't very much, but the fidelity — presuming the cartridge's filtering is as significantly better than the onboard filtering as they claim — should be exquisite.) The sequencer expansion should run about £70 and the new sampling cartridge about £150.

Lastly, of course, they are working on more sound disks. It seems to be the sampling manufacturer's curse, this creation of a reasonable and available library of samples. But Ensoniq has hired one person full-time to deal strictly with the expansion of their currently small line (currently four disks). Two more critical bits of information, now.

Bit one: disks hold more than samples and sequences. They also hold PROGRAMS, up to four per keyboard-half. These are presets that control the filters, modulation, sampling parameters, and envelope settings, and you can call up any one of them at any time and apply it to a given wavesample/sound, as if it were a coloured lens and the wavesample were light. A couple of quick presses, when you are practiced, is all it takes to slap a new program in place. This is convenient and powerful and means you've got dozens of sounds available to you, in terms of arranging and playing, with only a few base wavesamples in place.

Bit two: I really like the Ensoniq. It would be a credible instrument at twice the price (except for the keyboard), and may well become as ubiquitous, thanks to its price, as that other instrument that broke the perceived price/quality barrier, the DX7.

Not that it couldn't be improved: other inventive boffins (those with a properly opportunistic sense of capitalism) will even now be hard at work on extending the RAM, adding multiple outputs, and painting racing stripes down the microprocessors. More power to them; but my bet is Yannes and Charpentier will beat them to it.

ENSONIQ mirage sampling keyboard £1695

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