Digital Audio Tape (DAT) (part 1)
With DAT poised to make the leap from the professional recording studio to the world at large, David Mellor looks at the benefits of the new format to home recording.
Several years ago I heard a rumour that Sony intended to make analogue tape obsolete, in all formats from studio multitrack down to personal stereo. Sony have undoubted experience in designing audio and video equipment that is technically way ahead of what the other manufacturers are able to do, but their marketing success rate hasnt been totally 100%. Witness the Beta and Video 8 video cassette systems. It was Sony who pushed the Rotary Head Digital Audio Tape system - R-DAT for short - into being in 1983, in prototype form. So far, it hasnt achieved anything like the success, in terms of sales, that you might expect from its undoubted qualities of convenience and sonic accuracy. Is DAT destined for universal acceptance, consigning the existing Compact Cassette to the consumer dustbin, or will DAT stay solely in the studio domain as a mastering medium? One could say that time will tell, but of course time has nothing to do with it. Its the man or woman in the street who votes with his or her credit card. If they find it attractive, then DAT stands every chance of becoming as ubiquitous as the standard cassette. If DAT gets the thumbs down, then doubtless the manufacturers will go back to the drawing board and come up with another digital recording format which they hope will sweep the world. In my opinion DAT deserves to succeed, and the Compact Cassette has had a damn good run and is more than ready for retirement. But lets look at DAT in more detail, to see how and why it came about, and to find out what advantages it offers to the people who create music, and to the people who listen.
To understand why we need DAT, we first of all have to consider why the Compact Cassette system came about many years ago. (Compact Cassette is actually the full title of those plastic things you stuff in your Walkman). Philips, who invented the Compact Cassette back in the early 60s, only ever intended the medium as a low quality fun system. It certainly was plenty of fun, as the sales figures show, but the sound quality of the early machines was absolutely dreadful.
The human brain is a strange organ. Why is its undoubted power and resourcefulness so often directed towards impossible tasks? Manufacturers decided that they would attempt to find a place for the Compact Cassette in the home hifi system alongside the record player and radio tuner, which can both achieve a far higher sound quality on a good day. The first attempts didnt achieve an awful lot, but then along came Mr Ray Dolby with his famous switch. Activate the Dolby B circuitry on record and playback and the hiss produced by the inadequacies of the medium is reduced very nearly to a quarter of what it was before. There have been many other developments since then and these days the cassette can achieve a reasonably satisfying sound - when it is working at its best. But life being what it is the tape heads wear, guides shift out of alignment, the tape warps and stretches. Very soon what you have is a travesty of what the recording should have been like. By the 1980s, the time was ripe to develop a system which would do away with all these problems.