Luxman KD-117 DAT Deck Review

Technically a “prototype” here, though available in Japan, the Luxman KD-117 digital audio tape deck is in all but name a finished audiophile product, right down to a reasonably well-written instruction manual and an extraordinarily flexible wireless remote control that can even be used to control two KD-117’s simultaneously.

The tiny DAT cassettes, which measure approximately 2-7/8 inches long and 2-1/2 inches wide, are dropped into the same kind of slide-out drawer popularized by CD players. Despite their diminutive size, dat cassettes can hold up to two hours of uninterrupted music. Fidelity of reproduction fully equal to that of compact discs is made possible by the use of 16-bit linear quantizing at a sampling rate of 48 kHz. Microscopically narrow tracks are recorded by a pair of rotating heads mounted so that they scan the tape helically, as in a vcr.

To handle the tape properly, the KD-117 uses four direct-drive motors in its transport and three more motors in its loading system. A single pair of sendust-and-ferrite heads is used for record and playback, so no immediate comparison between source and recorded result is possible. A separate erase head is not required because the extremely high frequencies used for recording a tape automatically erase any previous signal.

A pair of twenty-segment-per-channel peak-holding fluorescent displays, calibrated from — 60 to 0 dB, show the signal levels. Levels higher than — 4 dB are shown in red, and an attempt to exceed 0 dB lights up an additional over indicator. The over point corresponds to the onset of clipping in the deck’s analog output circuits. Digital clipping, which could produce random effects, is thus precluded.

The KD-117 has two user-selectable time displays. One counts from the start of the tape, the other from the beginning of the current selection. The program number of the current selection is also shown, and the memory can hold any sequence of up to twenty-four selections. As a rough guide to tape remaining, indicators calibrated at 10-minute intervals are provided.

The user can insert start and SKIP markers (ID’s) at any point in tapes recorded on the KD-117. These marks are stored in the subcode fields on the tape and can be added (or deleted) either during the original recording or during a subsequent playback. For example, if you recorded an fm broadcast that was interrupted by a commerical, you could place a skip ID at the start of the announcement and a start ID at the point where the music resumed. Thereafter, the KD-117 would automatically fast-forward past the commercial.

In addition to the conventional analog line inputs and outputs, the KD-117 has digital and even optical jacks. As the deck will not record at the CD sampling rate of 44.1 kHz, use of the digital input jacks requires a second dat deck. A CD can be dubbed by recording the player’s analog output, however, and we found this to give entirely satisfactory results with a good CD player.

As we have (annoyingly) found with other DAT machines, the KD-117 has no playback level control except for its headphone jack. In addition to its normal record-level control for the line inputs, however, there is a special CD input with a pair of screwdriver-adjustable level controls that allow you to match the input from a CD with the output from the recorder. A switchable input filter is also provided for the CD jacks to eliminate any supersonic signals that might create spurious tones during dubbing.

The KD-117 presents a low profile, measuring 17-1/14 x 3-1/2 x 13 inches. It weighs a little over 19 pounds. While obviously no retail price has been established, the list price will probably be around $2,000.

Lab Tests

We checked the playback response of the KD-117 with a Sony TY-7551 tape that provides calibrated test tones at 20, 100, 1,000, 10,000, and 20,000 Hz. As the variations between 20 and 20,000 Hz were within 0.1 dB, no meaningful graph could be printed here. Indeed, as the corresponding entries in the “Laboratory Measurements” box show, the overall record-playback response was essentially the same, the maximum deviation from ideal flatness being ±0.3 dB. This result is particularly impressive since dat decks must include a very steep input filter to eliminate all signal components above 24,000 Hz.

The other parameters we checked were no less impressive. Naturally, there was no detectable wow-and-flutter; the digital process itself precludes that. But the playback and record-playback signal-to-noise ratios and total-harmonic-distortion percentages we measured indicated absolutely nominal functioning of a 16-bit linear system. Crosstalk rejection was no less than superb, and interchannel phase shifts were negligible up to the highest half octave, where they never exceeded 90 degrees. The only measurement that we found at all questionable was of recording sensitivity. The KD-117 required 1.05 volts input to reach its maximum record level, which presents no problem if you’re recording the output of CD players but is on the high side for some preamplifier tape outputs.

Comments

We found the KD-117 somewhat easier to use than most of the other DAT machines we have been able to test so far. While part of this ease may be attributed to our increasing familiarity with such machines and the presence of a readable instruction manual for this one, much of the credit goes to Luxman’s good, intuitively clear design.

When it comes to the sound, we have certainly heard no better. Dubbing CD’s—even with the extra digital-to-analog and analog-to-digital conversion stages required—produced no sonic degradation that we could detect even with the most stringent listening tests. Both in playback of prerecorded dat’s and with our own dubs, the quadruple-oversampling playback filter in the KD-117 certainly eliminated any of the alleged “digital” defects of simpler output-filtering systems. Imaging was superb, and all frequencies were solid and smooth from one end of the audio spectrum to the other.

The pleasure of being able to sit down to hear two hours of music put together according to my own taste was enormous. I only wish that I didn’t have to send the test sample back—and that U.S. consumers were able to buy their own digital tape recorders.

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