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Sony DTC55ES DAT Recorder

Article from Sound On Sound, February 1991

Sony's DTC55ES is their contribution to the first wave of domestic DAT recorders. Richard Aaron looks at what it can offer in a recording context.

Whatever else the 1980s will be remembered for, there can be little doubt that from a technological point of view it was the decade in which digitisation began its relentless transformation of our lives and the everyday objects with which we surround ourselves. In fact, looking back at the speed and effectiveness of the digital revolution, it is perhaps not surprising that a certain degree of nostalgia for analogue equipment should have emerged in recent years — whether this is based on real or illusory differences in performance.

What is much more surprising, indeed, faintly ridiculous when you think about it, is that anyone should think they would be able to halt the development of the digital audio tape recorder once it became a technological possibility. Imagine a world in which almost everything electronic had been redesigned in digital form (you need only project your mind a few years into the future) — with the sole exception of the tape recorder.

And yet, as we all know, this is precisely what some people in the music business believed possible, so convinced were they that the recent downturn in profits was a result of home taping rather than their own blinkered attitude to fostering and encouraging new music. Indeed, it is only within the past few months that the future of digital recording on DAT machines has looked anything like assured. As little as a year ago it would have been a brave man who said with any confidence that DAT recorders would not go the same way as 8-track cartridges, Betamax VCRs or video discs. Only with the continued interest in the format by manufacturers such as Sony and Casio and the recent arrival of mass-market machines in the hi-fi stores has the question mark hanging over DAT begun to be lifted.


If recent announcements from Philips are anything to go by, this hasn't come a moment too soon. Showing an almost touching commitment to their 30 year-old brainchild, the compact cassette, the R&D department at Eindhoven have developed a digital audio tape recorder which uses standard (in size, if not construction) cassettes. Details are still a little sketchy, but it appears that the machines will be able to play conventional audio cassettes in addition to those recorded digitally and are likely to enter the market somewhere below the price of the cheapest DAT machines.

Needless to say, this is bound to prove an attractive format, particularly on the domestic front where the prospect of a single recording machine which could provide you with a CD quality cassette for the home and a standard cassette for the car will seem like a dream come true for many people.

However, whatever the merits of the system, when it does finally arrive it is going to find itself in competition with the already well-established DAT format, and established DAT recorder designs of which a leading contender (in the domestic market) seems likely to be the new DTC55ES from Sony. With its classic hi-fi styling, remote control and a wealth of operating features, this, clearly, is DAT for the serious audiophile — a machine which, unlike so many 'pro' DAT designs, would not look out of place in your living room, and which will match your CD player for quality, ease of use and convenience.

But can it hold its own in the studio? After all, the lines between domestic and professional equipment have become increasingly blurred in recent years, and there must be more than one commercial studio using good quality hi-fi gear somewhere in its audio chain. But before we begin our appraisal let's get a little bad news out of the way... The Serial Copy Management System, designed to prevent anything beyond first generation digital recording on DAT machines, is firmly in place on the 55ES. As David Mellor explained in his excellent article on DAT in the November issue of SOS, this means that second and third generation digital clones simply cannot be made. Even a piece of music conceived, written and performed by you cannot be digitally copied more than once. Using the alternative analogue inputs, you can make repeated analogue recordings, but of course, this is accompanied by an inevitable loss of quality.

I mention this from the outset as this is the kind of restriction liable to render the 55ES unsuitable for many professional studio applications. On the other hand, a standard audio cassette is, for most us, likely to be the final destination for our recordings anyway, and SCMS, infuriating as it might be, clearly does not represent any serious drawback. Unless and until A&R departments and others decide to acquire DAT machines (...unlikely), having a single DAT quality master would, I'm sure, be sufficient for most people's purposes. And in that light the new Sony machine could well prove a valuable investment. So let's take a closer look...

"SCMS, infuriating as it might be, clearly does not represent any serious drawback. Until DAT machines are far more common, the facility to produce a single DAT quality master would, I'm sure, be sufficient for most people's purposes."


At the heart of the DTC5SES is a High Density Linear A-to-D convertor which, according to the people at Sony, cuts down on conversion noise produced by conventional A-to-D processing and makes possible the use of less severe filtering techniques. This, in turn, leads to improved phase response and a more 'mellow' tone. In other words, Sony have come up with what they believe is a solution to the problem of the overly bright sound of many early DAT recorders. We shall see.

Another major feature is the choice of three sampling frequencies — 48, 44.1 and 32kHz — the first for recording and playback of analogue signals in standard play mode, the second for recording and playback of digital signals (from CD or pre-recorded DAT tapes, for example); and the third for recording and playback of analogue signals in Long Play mode.

Rather like its namesake on VHS video machines, the Long Play function effectively doubles recording and playback time, giving you a total tape run of four hours from a 120 DAT cassette. Inevitably, this involves some sacrifice in audio quality: whilst signal to noise ratio and dynamic range figures are not significantly affected, to upper frequency response limit drops from 22kHz down to 14.5kHz, and harmonic distortion rises from 0.005% at 1 kHz to just under 0.08kHz.

In practice, there's no doubt the drop in quality is apparent if you try a back-to-back comparison, but on a couple of occasions I forgot I was in Long Play mode, and noticed nothing amiss until I returned to the machine. And I have to say, switching back to standard play at that point actually made the recordings sound rather too bright.

Of course, I can't imagine anyone in the studio deliberately limiting bandwidth simply to extend tape time, but as a feature on a domestic machine, there's no doubt the long play option is a very useful to have around. Other useful features are the ability to rewrite sub codes such as start, skip, end and program numbers after a recording has been completed.

Obviously, rearranging playback order, omitting certain tracks and listening to the beginning of each track as you scan through them (all of which the 55ES is capable of doing) are the sort of features designed to appeal to the domestic market, but the ability to edit sub codes after recording does make this a much more versatile studio machine. You can, for example, insert (with great accuracy) start and end ID codes to play back or omit a certain section of a song. By utilising absolute time sub codes you can determine your precise position on tape and how much tape you have remaining — and begin playback or end a track at a particular point in absolute time (calculated from the start of the tape). All studio-friendly functions.

"Though studio machines can usually be relied upon to out-perform their domestic counterparts sonically, in terms of construction and reliability I find high quality hi-fi equipment frequently eclipses 'professional' gear."

In addition, it is possible to program muted portions of tape (and with a S/N ratio of over 92dB, we're talking silence here), and fade ins and outs adjustable in duration from 0.2 to 15 seconds. There's also a repeat play facility which allows you to repeat a selection of tracks on the tape, or a section of music within a particular track. Left to its own devices, the DTC55ES will replay the desired portion of tape 16 times, but of course you can cancel this at any point should you not require so many repeats. An auto-play function will automatically switch the machine into play mode after rewinding and (providing the absolute time code is still intact), fast forward or rewind the tape by a predetermined amount using the time search facility.


As befits its status as a domestic machine, the DTC55ES is styled to blend in with hi-fi gear rather than studio equipment (which is perhaps no bad thing) and this is reflected in its layout. The rear panel is home only to the analogue line in/out phonos (for connection to a stereo amp or mixing desk/power amp) and the coaxial/optical digital in and optical digital out sockets (for connection to a CD or other digital equipment). Everything else is situated on a neat, if rather crowded, front panel. No-one who has ever used a cassette deck should have any problem with the transport controls — everything is quite conventional, with play, record, stop and pause buttons and fast forward/rewind controls which may be used for cueing when switched to play.

Not quite so conventional — even by DAT standards — is the tape loading system. After placing the cassette into the loading carriage horizontally, facing forwards, and pressing the close button, it is taken in, rotated out of the horizontal plane, and then played at approximately 45 degrees to the vertical. The entire loading chamber is lit so that the cassette may be seen in operation, but if the idea of this is to allow you to keep a check on how much tape is present on each spool (and really, that can be the only purpose), I have to say I found it very difficult to see on the Maxell and Fuji tapes I tried with the machine. In any case, the provision of such an elaborate tape position indicator (with readouts for absolute time, program time and tape remaining) would make this quite unnecessary. Still, it does look the business...

On any machine of this complexity, having an informative, easily read display is absolutely essential and I'm pleased to say the DTC55ES acquits itself well in this department. With its long — very long in fact — input LED ladders, digital counter and sub code ID sections, it imparts a tremendous amount of information. It even advises you of the opening and closing of the tape loading carriage. Alongside, there's a 'table of contents' indicator, designed to work with pre-recorded DAT tapes (although at present only a handful of artistes on Factory Records seem to have material released on this format), and an input select and sampling frequency indicator.

You can read most of the display from quite a distance away, a bonus in the studio, and with virtually all the front panel controls duplicated on the remote unit, you could locate the machine in an otherwise inaccessible position — particularly if you are using two hour tapes which don't require changing very often.

"A domestic machine it may be, but inside there's a first class piece of studio gear ready to do your bidding — and if you can take it into the lounge after a long day in the studio, who's complaining?"


Construction, generally, is first class, which relates to what I said earlier about it being no bad thing that the machine is aimed at the hi-fi market. Though studio machines can usually be relied upon to out-perform their domestic counterparts sonically, in terms of construction and reliability I find high quality hi-fi equipment frequently eclipses 'professional' gear. Whether this is because it is designed to be moron-proof I wouldn't like to say, but standards definitely seem to be higher in the hi-fi world in this respect — and the Sony DTC-55ES is no exception.

Of course, this would be of little value if the machine didn't record and playback music with the accuracy we have come to expect from digital equipment. So how does the Sony perform, and how does that high density linear convertor affect overall sound quality? Well, as you will appreciate, the absence of a similar Sony machine without this feature makes it a little difficult deciding how much the convertor contributes to the sound. After all, there have been a number of recent DAT machines which don't suffer from an overly bright sound which haven't been blessed with this particular innovation. But there can be no doubt that the Sony machine has a remarkably refined tonal balance, and quite extraordinary depth and clarity. Top end definition is impressive too, and I could detect none of the edginess which opponents of digital sound so often draw attention to.

In fact, I could find no-one who could distinguish between pieces of music played 'live' and recorded on the DTC55ES with anything like convincing regularity, and I have to include myself in that category. Certainly, digital recordings made from CD were quite impossible to distinguish from disc (which, of course, is what the record companies were so worried about in the first place).

Results were not quite so impressive recording via the analogue inputs, but in a back-to-back comparison with my Tascam cassette deck and Maxell XLII tape... well, let's just say there was no comparison, not at the DTC's standard recording speed anyway. Noise and distortion levels which I had always believed pretty acceptable on the cassette deck seemed to envelope the music like a woollen blanket and make you long to switch back to the DAT recording.

I suppose you could argue that the comparison isn't really valid: the cassette machine cost less than half the price of the DTC55ES, and it is based on technology some 30 years old. But clearly, many people considering the purchase of a DAT recorder for the studio will be looking to use it to replace a cassette mastering machine, and it is how much of an improvement it represents in this respect that will be of primary interest to most of them. Of course, SCMS is sat there waiting to pour cold water over the proceedings: at the end of the day, the rest of the world is still likely to be introduced to your music via an analogue cassette recording. But I think most people would be content in the knowledge that they at least had their master on DAT; they could, after all, have it copied digitally by a studio with a non-SCMS machine.

I have to say I found it somewhat annoying to see SCMS described in the user manual as some kind of positive feature which actually 'allowed' you to do something (record a first generation digital copy) rather than one that prevented you from doing something else (make a number of copies of a piece of music you may have written and recorded). But I suppose that's the price you pay for buying a domestic machine. Anyone not involved in studio work would almost certainly be engaged in nefarious activities of some kind if they needed to make multiple digital copies of a recording. And that's what the system is designed to prevent.

But really, this is as close as I could get to a criticism of the DTC55ES. A domestic machine it may be, but inside there's a first class piece of studio gear ready to do your bidding — and if you can take it into the lounge after a long day in the studio, who's complaining? Of course, there are a number of features which you're seldom likely to require in the studio, but with a retail price of under £550, it can't be said you're being asked to pay much for them. Also, many of the other features — particularly the programming of sub codes after recording — could prove extremely useful, particularly if you've any intention of using the machine as an aid to sampling.


There is a school of thought which would advise you to wait for the price of DAT recorders to fall even further before entering the market. And it has to be said, the £250 machine will almost certainly emerge within the next year or two. But all things considered, I'd say this was a pretty good time to take the plunge. The future of DAT finally seems assured (the challenge from Philips notwithstanding), and the arrival of third generation machines has laid to rest many of the early criticisms of DAT as a rather sterile recording medium. As a representative of this new generation, the DTC55ES has no real peers at the price. I would recommend it unreservedly.


£549.99 inc VAT.

Sony UK, (Contact Details).

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Shape Of Things To Come

Next article in this issue

McGill University Master Samples

Publisher: Sound On Sound - SOS Publications Ltd.
The contents of this magazine are re-published here with the kind permission of SOS Publications Ltd.

The current copyright owner/s of this content may differ from the originally published copyright notice.
More details on copyright ownership...


Sound On Sound - Feb 1991

Donated by: Bert Jansch / Adam Jansch

Gear in this article:

DAT Player/Recorder > Sony > DTC55ES

Review by Richard Aaron

Previous article in this issue:

> Shape Of Things To Come

Next article in this issue:

> McGill University Master Sam...

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