Optimus DCT-2000 DCC Recorder Review

The Texas-built Optimus DCT-2000 is the second Digital Compact Cassette recorder to hit the bench at Hammer Laboratories, just weeks after the Philips DCC900. It may surprise some readers to see Radio Shack on the leading edge of DCC technology, but Tandy Corporation, its parent company, was the first hardware manufacturer to join Philips on the DCC bandwagon, so it makes perfect sense that Radio Shack’s Optimus recorder is among the first on the market.

But even as an early entrant, the DCT-2000 has a clean appearance and no-nonsense construction that suggest thorough engineering. Clearly, the Tandy designers focused on streamlined function rather than cosmetic frills. Still, DCC technology is almost thirty years beyond the analog cassette, so even a modest DCC recorder such as this one boasts some high-powered features, not to mention high-quality sonics.

The DCT-2000's front panel is concise indeed. Nevertheless, all the primary transport controls are at hand, with six large buttons for drawer open/close, record, pause, tape direction, play, and stop. Underneath are six smaller buttons, including fast-forward, rewind, and forward and backward track-skip. A reverse-mode button enables you to select single-side, dual-side, or continuous-autoreverse operation. And a recording-mute button inserts a 4-second blank on the tape (or a longer one if you hold the button down)—useful for separating tracks or editing a false start. You’ll also find a headphone jack, headphone level control, and power switch.

Lesser controls are hidden behind a flip-down panel. A slide switch selects analog, coaxial digital, or optical digital input, while another selects Dolby B or C noise reduction (or no noise reduction) for playback of analog cassettes. There is a knob to adjust the analog input level, another for channel balance during recording, and no fewer than eight buttons dedicated to the manipulation of ID markers, which are cueing signals written to a DCC tape’s subcode track to help in locating specific points on a recording. When the Auto-ID button is engaged, the deck automatically writes a start marker at the beginning of the tape, track numbers at the beginnings of selections, a tape-reverse marker at the end of a side, and a start marker at the beginning of the next tape side. Using six different write and erase buttons, you can add, delete, or edit a tape’s start, reverse, and skip markers. (A skip marker tells the transport to fast-wind until it encounters the next start marker.) In addition, a renumber button can be used to reorder the track numbers on an edited tape.

Incidentally, in addition to recording and playing stereo DCC tapes, the DCT-2000 will play special prerecorded DCC tapes carrying four mono tracks (labeled A through D), for a total playing time of as long as 3 hours.

The DCT-2000’s blue fluorescent display is controlled with three buttons. The display automatically shows the current track number for DCC tapes, and the mode button can select a readout (in hours, minutes, and seconds) from one of four timers—total elapsed or remaining time and elapsed or remaining track time. You can also select a tape counter, which is all you get for analog tapes; the reset button sets the counter display to zero.

Prerecorded DCC tapes can hold a fair amount of textual information along with the music (as much as six hundred characters per second). You can bring up twelve characters at a time on the display with the text button; the mode button enables you to sequence through the album title, track titles, and album credits. The display also has two bar graphs showing recording level for the left and right channels, scaled from -40 to +10 dB for analog cassettes and — 50 to 0 dB for digital. A handy numerical readout keeps track of the highest signal level during a recording. Numerous other icons and messages keep the user well-informed about the deck’s operational status.

The program button enables you to select as many as twenty individual tracks on a DCC tape for playback. You can’t program out-of-order playback, however. For example, if you choose Tracks 5, 2, and 7, the deck will play Track 2 first, then Track 5, and then Track 7.

The supplied wireless remote is very compact (and consequently easy to lose between the cushions of your sofa). Its twelve buttons duplicate the front-panel play, pause, stop, direction, track-skip, fast-wind, record, record-mute, display-mode, and text buttons.

The DCT-2000’s back panel sports the expected complement of connectors. Four phono jacks provide line-level analog input and output, while two morejacks provide 75-ohm coaxial digital input and output using the standard multiplexed SPDIF interface. Two Toslink connectors permit digital input and output through fiberoptic cables. The digital inputs can be used to make direct digital recordings from a CD, DAT, or DCC player with digital outputs, eliminating a signal-degrading cycle of digital-to-analog (D/A) and analog-to-digital (A/D) conversion. (The Serial Copy Management System, or SCMS, will prevent the resulting tape copies from being copied again digitally, however.) Finally, the DCT-2000 has a rear-panel switch to turn its wireless remote-control circuit on and off.

A look inside the DCT-2000 revealed a main printed-circuit board with two plug-in cards, a power-sup-ply board, and a front-panel board. The primary chip set consists of eight Philips DCC, A/D, and D/A chips, along with a Motorola microprocessor. Although the layout is tidy, there are several very long wiring harnesses that should have been trimmed to proper length instead of being coiled up and tied back. The tape transport is housed in a plastic chassis, but the inner mechanism surrounding the reversible tape head is made of metal. Overall, the DCT-2000 is not a technological work of art but a good piece of utilitarian engineering.

The deck performed very well in both digital and analog modes. Digital playback, for example, was extremely CD-like, with almost perfectly flat frequency response, high signal-to-noise ratio, wide (though not extraordinary) channel separation, very low distortion, and outstanding low-level linearity. The digital record/playback measurements, using an analog input signal, were almost as good, which is remarkable considering the A/D converter and other electronics added to the chain. The main differences were a reduction in signal-to-noise ratio, a doubling of the distortion (to a still inconsequential 0.0067 percent), and a surprisingly tiny 0.2-dB increase in low-level nonlinearity (to a total error of 0.6 dB)—a tribute, perhaps, to the quality of the Philips Bitstream l-bit A/D and D/A converters. All in all, it’s a superb set of measurements.

Analog playback performance was, as one would expect, clearly inferior to the digital performance and about on a par with that of a good mid-line analog cassette deck. Frequency response was ragged at the low end, with a 4-dB deviation at 32 Hz, but smoothed out at higher frequencies. Signal-to-noise ratio, both with and without noise reduction, was good for an analog deck. Channel separation was adequate, but no better, and distortion was unusually high.

Mechanical checks and measurements showed that the deck's fast-wind time was reasonable, and though speed error and wow-and-flutter in analog playback were on the high side, we would rate the transport’s overall performance as acceptable. We hope later models show some improvement in these categories, however. In digital playback, speed error and wow-and-flutter were below the resolution of our Audio Precision test system.

Although the DCT-2000's measured performance in digital mode was reassuring, we cannot infer as much from the measurements about the deck’s sound quality as we could in the case of a CD player or DAT deck. The reason is that the DCC format is built around a perceptual-coding system known as PASC (for Precision Adaptive Sub-band Coding), which is designed to record signals in a way tailored to how we actually hear. For example, sounds that are too soft to be heard or that would be masked by louder sounds at nearby frequencies are not recorded at all, freeing up space on the tape for more accurate recording of the sounds that are audible. How successful the system is at distinguishing between what will be audible and what won’t be is something that can be determined only by careful, controlled listening. That, in fact, is how PASC was tested during development.

To evaluate the DCT-2000’s sonic performance, I inserted it in a high-quality audio system including an excellent CD player, the Marantz CD-11mkII, as the sonic reference. I digitally recorded several CD’s onto the DCT-2000, then compared the taped copies with the originals. The analog output signals were carefully matched in level and switched with an ABX blind-comparator box, which enabled me to compare the entire playback signal chains, including the D/A converters and analog output stages of the CD player and DCC deck.

I listened to a wide variety of music but focused on classical music because its wide dynamic range is useful for exposing both high- and low-level distortion, as well as the noise floor (most pop music is useless for these purposes, though usually better for dancing). After many hours of critical listening, I concluded that with most music I could not reliably hear any difference between the original CD and the DCC copy. With one recording, however, of solo harpsichord, I was able to identify the players successfully about 80 percent of the time, indicating that a very slight difference did exist. On the other hand, I had no preference for one over the other; there was just a barely distinguishable difference.

Whether the difference I heard in that one case resulted from an artifact of the PASC system or from something more mundane, such as a small frequency-response discrepancy between the D/A converters or output stages of the two machines (a very common cause of subtle sonic differences between components), is impossible to tell without a more thorough investigation. It was, in any event, a very, very minor effect. The deck’s playback of analog cassettes was good, but not as good as that of high-end analog-only cassette decks.

I had a number of reservations about the mechanical operation of the deck. For example, it did not anticipate the shortest distance to a selected track on the opposite side of the tape: It would fast-forward to the end of the tape, then reverse and fast-wind to the desired track, regardless of where it was located in relation to the starting point of the search. That entirely defeats what is supposed to be one of DCC’s benefits—smart track search.

When we selected a new DCC track during playback, the display showed how many tracks we skipped beyond the current one instead of the actual track numbers. For example, if you’re playing Track 10 and then select Track 15 with the track-skip button, while the deck searches for the new track the display will show “1,2,3,4,5” instead of “11,12,13,14,15.” This is very annoying: The machine should be doing the mental arithmetic, not the user. Even worse, when you’re playing an analog cassette, you can skip only one track at a time.

The DCT-2000 took about 10 seconds to close its drawer, load a DCC tape, check the contents, and start playback—a rather tiresome wait for anyone accustomed to CD or analog cassette. Moreover, during the checking process there was brief low-level audio output, which should have been muted. I was also bothered by all the loud, low-tech solenoid clicking that went on during the loading process. As with other DCC decks I’ve seen, the DCT-2000’s mechanical performance simply doesn’t do justice to its sound quality.

On the plus side, the DCT-2000 did not exhibit any of the head-clogging with analog cassettes that we ran into with the Philips DCC900 reviewed last month. I ran many hours of analog and digital tapes through the machine without observing any dropouts or increase in errors. Preproduction units, such as the DCC900 sample we tested, often exhibit operational quirks that vanish in production models, like the DCT-2000 reviewed here, and we now suspect that the problems we encountered with the Philips deck were a fluke.

Overall, the Optimus DCT-2000 is very mature for a first-generation product. The Tandy engineers did their homework and have brought forth a very competitive recorder. Given the high state of competition from CD, DAT, and analog cassette recorders, this is quite an accomplishment. In particular, the sonic performance of the PASC system is remarkable and points to a not-so-distant time when perceptual encoding will outperform linear coding and become the norm. And the DCT-2000, along with its fellow DCC decks, does something that approaches magic in ourformat-a-month age of incompatibility: It accepts both analog and digital tape. That is DCC’s greatest strength, and it is a remarkable one.

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