London's Air Studios have installed a Fairlight III in their special computer room. Paul Colbert caught a lift to the upper reaches of Oxford Street to learn what they do with it, where they put it, and why III is better than I.

MENTION OF the word 'Fairlight' a few years back would have had superstitious types crossing themselves.

Since then, Emulators, cheap sequencers, samplers and digital synths have taken a large byte (ha, ha) out of the Fairlight's mystic. But the name does have a certain authority... So what do you get for your money?

The series III (popularly known as the Turbo System) may resemble the original late seventies model in format, but wildly outdistances it in three principal areas — sound quality, memory and a re-trafficed structure to how its sounds are produced.

There's actually no great mystery to sampling. Essentially, the more memory, the better the resulting noises. Compact Discs sample in their own way, operating at a rate of 44.1KHz. (For technical reasons — mainly leaving room to take out nasty side effects — the sampling rate is generally just over twice that of the highest frequency you can record.) Since the upper limit of hearing is 20KHz, the sums are easy and most experts safely tell us CD is as good as we could possibly want, or appreciate.

With typical, one-up earmanship, AES (Audio Engineering Society) fixed 48KHz as the desirable standard.

At top whack the series III samples at 100KHz.

Knock it down to CD's mere 44.1 and it will record two and a half minutes worth of music. That's 2.5 minutes worth of digitally recorded music, NOT sequenced stuff, but actual sound whose every split second can be radically edited.

The series III employs 14M (Megabytes) of RAM (Random Access Memory) to do that... a colossal amount by present standards. Converting your average rack mounted delay line to 44.1KHz (if it were possible) would give you no more than half a second, if you were lucky.

Why anyone should bother with a 100KHz rate is more a sign of manufacturing prowess than design standards. Sampled information, whether off RAM or CD, needs help from a sophisticated filter network to put it back together again. Chip memory is already the cheapest, mass-produced lump of any computer. And, the higher the sampling rate, the less the demand on the filter network.

So it's not long before it becomes cheaper to inflate the sampling rate with cheap memory than to build clever filters at the far end.

In the original Fairlight — as in this one — a series of voice cards create the actual sound under instructions from a CPU (Central Processing Unit). Unlike the III, the first Fairlight asked the voice cards to hold the samples in their own memories.

The III keeps the samples in its own bulk RAM (the 14M) then doles it out to the voice cards only when needed under instructions from the CPU. Result: larger and more versatile memory, making it much easier to split sounds across the keyboard.

Don't expect to see a burgeoning secondhand market in Is, but there are already signs of musicianly lionising of the original. For example, one trick both machines can play is to analyse the waveform of the digital recording and resynthesise the sound by building up a replica from its own collection of harmonic generators. The III gets it almost perfect, whereas the I got it wrong, false, obviously electronic and a bit vocoderish. Of course some people now prefer the weirdness of the original and have already begun to lament its passing.

Technically the guts of the Fairlight looks like this: a dual 6809 central processor, two 6800s for waveform processing and general interface stuff, and two further 6809s as channel processors. There's more, but that's the heart of the system which leaves you with 512K of system RAM to run the business, 16K for video, 512K for waveform processing, 64K on each channel card (another eight) plus the mighty 14M for sampling. You could run a small company on that amount of computer power, if it wasn't music dedicated. In comparison, a good IBM personal micro will boast ½M of RAM.

At one time it was the sound editing facilities of the Fairlight that caught the public's imagination — the ability to get 'inside' a grand piano, display the waveform as a 3-D representation of harmonics decaying in time, then remodel the sample to your own base desires. Pianos were spliced into broken glass, and unthinkable and largely unpleasant experiments were carried out on recordings of the most personal human functions. Air's aficionados believe that side of the Fairlight's character holds less fascination today. Instead users are obsessed with producing the very highest quality samples. Much of the early waveform tinkering was to repair bad samples anyhow.

Get a good sample to begin with and it's not needed. And if you still insist on peculiar noises, the Fairlight III can quickly resample itself — you layer up a handful of different samples and get the computer to relog that array as one new noise.

But generally speaking, it takes a good studio to get good samples — not much point in recording 100KHz worth of stuff in a shed. Another reason why Fairlights tend to be owned by 'institutions' rather than individuals. There are 56,000 others, but we won't go into them.