Hi-fi formats come and go just like fashion. When on the ascendent they seem magnificent and unstoppable, set to take over the world. On the way down, no one really cares. In the case of Sony’s Digital Audio Tape format, this happened in the space of eighteen years. At the time of its launch in 1987, pundits where predicting that it would “wipe out” Compact Disc, and less than two decades later, Sony quietly dropped the format. This seems like an awfully long time now, but in truth – as a domestic hi-fi format – DAT had come and gone in the space of one half decade. In other words, it lasted about the same amount of time as an iPhone with a couple of minor spec tweaks.
Today, a few old DAT machines soldier on, but most are now discarded and defunct – lying around motionless, like props on a post-apocalyptic sci-fi movie. This was the future once, but not anymore. Indeed, the DAT format as a whole is emblematic of the nineteen eighties – a brave new world of technology that seemed so incredibly impressive back in the day, but now swings between quaint and ridiculous.
Nowadays, it’s hard to understand the reason for creating a complex new tape-based format that fuses Compact Cassette, video cassette and Compact Disc. Such were the forces playing out in the nineteen eighties however, that DAT seemed like a really rather good idea at the time. These days, we see anything cassette-based as quirky and ‘fun’, but a generation ago it was the staple diet of the music and video loving masses – a functional object that we took for granted. As far as recorded music was concerned, CD changed all this of course, but that was recorded music – and eighties musos were used to compiling their own top tracks. The ‘mixtape’ was the staple diet of music lovers; we made them in vast quantities, and by the late eighties the hi-fi industry was selling oceans of ‘high speed dubbing cassette decks’ designed to do precisely that. In this context, DAT made absolute sense; Sony would make it much smaller than Compact Cassette, and it would be able to copy things digitally – preserving a (supposedly) perfect facsimile of the original.
DAT’s the way
First surfacing in Japan in autumn 1987, and then slowly rolling out around the world for nearly another year, the new Digital Audio Tape format (sometimes called R-DAT, ‘R’ standing for recordable) used a 3.81mm magnetic tape inside what was effectively a miniaturised video cassette shell. DAT machines recorded and played uncompressed PCM digital at either 32, 44.1 or 48kHz at 12- or 16-bits; 16/48 was the absolute cutting edge at the time the format was introduced.
Unlike Compact Cassette, the format worked in one direction only, and was able to give up to 180 minutes per tape at 16/48 – although as with C120 cassettes, the longer length DATs were less reliable due to the thinness of the tape itself. Running in Long Play (LP) mode at 12-bit, 32kHz, it gave a massive six hours of recording onto a DAT 180. Unlike Compact Cassette, DAT shells had a clever locking system that effectively sealed out the outside world, when not in the machine. Respective tape speeds for SP and LP operation were 8.15mm/s and 4.075mm/s.
The format also had some provision for metadata, so track ID points could be stored, and there was an absolute time code. This meant that you could use DAT as you would with CD; there was a real and reliable track search function. The difference is that if you wanted to go from track 3 to track 15 on CD, it would take a second or two, whereas the DAT machine would physically have to wind through the tape – for up to thirty seconds or more. This seemed terrible to CD users, but back in 1987 most folk were used to cassette – and DAT was considerably faster searching than that! Nowadays of course, watching a DAT machine spool through an album in track search mode is a chore.
This is all the more remarkable when you consider how much more complex DAT was, compared to ye olde Compact Cassette. Born out of the massive amount of research and development work done for video cassette recorders, DAT uses a rotating head and helical scan to record data, allowing a higher density of data to be stored – so its tolerances are extremely high. Anything less would mean the format simply would not work, because it stores over 5 megabytes of data per minute, and that’s before you factor in the error correction system and other subcodes.
Aiwa’s XD-S1100 was the company’s third generation machine, from a manufacturer that had a top-tier reputation for tape recording garnered from its excellent analogue cassette decks. Indeed, so prestigious was Aiwa in the mid eighties that it gave the world the very first commercially available DAT recorder back in 1987, under the EXCELIA sub-brand. This deck arrived three years later in November 1990 in its native Japan, by which time the breed had been refined considerably – without all the costs being taken out of the products, which is what began to happen just a couple of years later.
The problem for the new XD-S1100 however, was that it was soon overshadowed by the more sexy (but generally less reliable) Sony machines. Also, around this time, the format was moving out of the home and taking to the streets, thanks to the arrival of Sony’s TCD-3 DAT portable in May 1991, and Aiwa’s own derivative of it, the HD-S1. The Aiwa’s crime was to have the wrong brand name, to have middling dealer support in the UK and Europe, and to have come out just when the novelty of compact, high quality home machines was wearing off. Also, the fitment of SCMS – Serial Copy Management System, which allowed users of all domestic decks only to make copies of CDs to DAT for their own use – dulled the appeal. This meant that if you recorded a CD to DAT, then tried to do a direct digital copy of that DAT, the unit wouldn’t record. Early DAT decks didn’t have this feature, but it surfaced as a result of a lawsuit from music rights holders, who – perhaps understandably – didn’t want perfect digital copies of their music in wide circulation.
Measuring 466x116x367.5mm and weighing 7.5kg, the Aiwa was either a high end budget design or budget high end one – depending from which end of the telescope you looked. It was certainly far more affordable than many machines on sale, and didn’t quite have the ‘hewn from granite’ build of more expensive competitors – yet it was still a quality item. Its 16-bit DACs yielded some impressive specs for the day, with and a quoted frequency response of 2Hz to 22kHz [at -0.5dB], a claimed signal-to-noise ratio of 90dB and a THD figure of 0.005%.
Lest we forget, this was startlingly good compared to the best Nakamichi high end cassette deck of the day, and better too than the best open reel. Wow and flutter was said to be “under the measurable limit.” It’s worth remembering just how cutting-edge DAT appeared back in the day, with dazzlingly good measured performance compared to what we were used to. In terms of features, the deck was average; it was most notable for having a pair of both coaxial and optical digital inputs and outputs. Most budget machines tended to skip on the coaxial digital output, at the very least. It also had an illuminated tape compartment, motorised loading drawer – which was pretty standard – and large, high resolution meters which made level setting quite easy. There was also a high speed search function by sub-code detection, letting the deck function – to an extent at least – in a way analogous to a CD player. Finally, it sported RCA unbalanced line outputs and a headphone out for monitoring.
Sonically it’s a very respectable sounding machine. Tape handling is relatively smooth – especially compared to earlier decks – and via its internal DAC the Aiwa makes a nice open and detailed sound. The great benefit is that DAC technology has raced along since the early nineties and you can easily plug it into a modern DAC such as a Chord Hugo, for example. This done, you get a far more musically articulate sound, with great depth, space and detail; the stock convertor sounds very shut-in by comparison.
For the standards of the day, when Compact Cassette was still a thing, it’s a remarkable sounding product that totally trounces almost all analogue tape machines. Still, things have come on apace and most buyers now will find the format too fiddly and potentially unreliable. That’s why in today’s world, the Aiwa’s XD-S1100 is very much a curio – and not entirely practical. If like me you have a large number of irreplaceable DAT tapes and want to transcribe them to CD or hard drive as .WAV files, this is a great machine but I can’t see many using Digital Audio Tape as a daily proposition nowadays – especially now that computer recording is so cheap and easy.
DAT was always too fussy for mainstream audiophile use, which is why it soon became the province of semi-pro studio users, where it was widely used as a mastering medium. Still, as a home recording technology it’s a fascinating flashback to a world where things had not yet worked themselves out. If you can find a good surviving example, Aiwa’s XD-S1100 is of real historical interest to collectors, as a great value usable DAT machine. Perhaps because it was only manufactured for two years, it never became a cult deck, so prices remain sensible; expect to pay no more than £200 for a mint, boxed machine like this, including its original remote control.
Digital Audio Tape was not, of course, the first digital audio tape. Many classical music fans will have come across Denon’s PCM classical recordings, done as early as 1972. These used a two-inch Quadruplex-format videotape recorder as a transport, and came from research dating back even earlier. In 1976, Soundstream developed a one-inch reel-to-reel tape transport manufactured by Honeywell, using the company’s own encoders and decoders running up to 16-bit, 50kHz sampling. Telarc Records used this for its 1978 recording of Holst’s Planet Suites – and it was the first fully digitally recorded commercial LP release. 3M’s Digital Mastering System was used for Aaron Copland’s Appalachian Spring in 1978, and then Ry Cooder’s Bop Till You Drop became the first fully digital rock recording in 1979, made at Warner Brothers Studio in California. The real heyday of tape-based digital recording was in the eighties, of course. Consumer video tape formats such as Sony’s Betamax were used in the EIAJ digital format, which sampled at 44.056kHz at 14-bit resolution. Sony’s PCM-F1 became a popular system from its launch in 1981, running at 16/44.056 and offering excellent sound. Sony’s DASH format and Mitsubishi’s ProDigi format used conventional open reel tape, recording digitally, and these become popular too.