Sony CDP-520ES CD-player Review

Since Sony introduced the CDP-101 Compact Disc player in 1983, at least two new “generations” of CD players have made their appearance. Each has been markedly superior to its predecessors in the important characteristics of error correction and ability to withstand physical shock and vibration without losing its tracking of the disc. There is disagreement about the sonic improvements that are said by some manufacturers to distinguish their new players from earlier designs or from competitive products using different design approaches. In testing perhaps a couple of dozen CD players, I have never found what I would consider to be a significant difference in sound quality among any of them—that is, I have never found a difference that clearly proves one player’s sound is superior to another’s.

There is no doubt, however, that in only a couple of years enormous strides have been made in improving the tracking reliability of CD players and in reducing their size, weight, and cost. Progress in these areas is due in part to the development of large-scale integrated circuits (LSI’s), each of which replaces a large number of smaller IC’s, transistors, and passive components. Paralleling this development have been improvements in the mechanical system that guides the laser beam along the spiral of submicroscopic pits on the disc.

The new Sony CDP-520ES is an excellent example of the state of the art in CD players, even though there is little in its external appearance to distinguish it from other, more mundane CD players. In keeping with current trends, the front panel of this low-profile player presents a rather subdued appearance, with a reasonably small number of flush-mounted pushbuttons and a modest fluorescent display that shows the usual information on track and index numbers, elapsed time of the current track, and remaining playing time on the disc. The horizontal disc drawer opens and closes with surprising rapidity on alternate touches of a button. It will also close if lightly pushed.

The CDP-520ES comes with an infrared remote control that not only duplicates most of the front-panel control functions but has the additional capability of accessing any track by direct entry of its number (doing this from the player’s front panel can require several operations). Other features are listed in the box on page 28.

It’s what’s inside the rather plain exterior of the CDP-520ES that accounts for its outstanding performance, however. The new circuitry, principally on third-generation LSI chips, includes a high-speed digital-to-analog (D/A) converter and a digital filter (a first for a Sony player). The Sony designers have used 88.2-kHz oversampling and high-order digital filtering to obtain an optimal combination of pass-band flatness, reduced beat-frequency intermodulation, and low noise. The new LSI’s are CMOS devices, which have very low power consumption and generate almost no heat. While these are not particularly important considerations in a home component, some of these same chips made possible Sony’s tiny portable CD player, the D-5.

The most striking quality of the CDP-520ES can be appreciated without even listening to it. Its new linear-motor tracking mechanism provides an extremely high-speed search capability—many times faster than that of any other CD player we have seen—together with more precise servo control of the laser beam. Instead of the conventional rotary motor that drives the optical system through gears, the Sony mechanism is driven directly by a linear motor that’s somewhat analogous to a loudspeaker’s voice coil (with an operating excursion of about 1-1/2 inches). Velocity feedback in the tracking servo allows the optical system to move across 50.000 “grooves” per second in its high-speed mode, slowing down automatically as it nears the selected track and stopping precisely above it. This fast-slewing process is aided by Sony’s new low-mass laser-pick-up system, which is a third the size and weight of previous systems.

The Sony CDP-520ES, finished in black, is 17 inches wide, 13-1/4 inches deep, and 3-1/4 inches high. It weighs approximately 14-3/4 pounds. The RM-D302 remote-control unit, powered by two AA batteries, measures 2-3/4 x 7 x 3/4 inches. Price: $600.

Lab Tests

The Sony CDP-520ES lived up to the manufacturer’s claims in full measure. The frequency response, measured with the sweep on the Philips TS3 test disc, was the flattest we have yet measured from a CD player. The two channels were identical (with just under 0.1 dB imbalance), having a truly unmeasurable output variation of perhaps 0.01 dB from 20 to 10,000 Hz, increasing to + 0.2 dB at 20,000 Hz. The interchannel phase shift of 43 degrees at 20.000 Hz is intermediate between the values we usually measure from CD players using separate D/A converters for the two 'channels and from those in which a single converter is multiplexed between the channels. This result suggests that Sony is multiplexing a single D/A converter but at double the usual frequency, thus halving the interchannel delay and the corresponding phase shift.

The electrical performance of the CDP-520ES was typical of the best of today’s CD players, with channel separation in the 105- to 114-dB range at most audible frequencies, a noise level of — 100 dB, and 1,000-Hz distortion readings of 0.0003 to 0.0004 percent. Flutter, of course, was unmeasurable (the reading was the 0.001-percent residual of our test equipment).

Like a couple of other top CD players we have tested recently, the CDP-520ES tracked all the calibrated disc defects on the Philips TS4A test disc and made the transition from Track 17 to Track 18 of that disc without clipping the opening syllable on the second track. Since there is no silent interval between those tracks, going from one to the other is a severe test of the cueing and demuting accuracy of a CD player; not many pass it unscathed. We also appreciated Sony’s volume control for the headphone jack, since the player could drive 600-ohm phones to an uncomfortably high level.

Our standard cueing-time test, from Track 1 to Track 15 of the Philips TS4 disc, confirmed the high speed of Sony’s linear servo. As nearly as we could measure it, the transition took only about 1.8 seconds, although part of that was probably startup time in the player after the button was pressed and another part our own reaction time in operating the stop watch. The slewing speed of the CDP-520ES was demonstrated much more dramatically when we programmed it to play the first and the last tracks on the Philips test disc (No. 1 and No. 25). In this case the transition was so fast we couldn’t really measure it—certainly it was no more than a fraction of a second. To appreciate the advance this high cueing speed represents, you need to have the experience of waiting for other players—even Sony’s earlier models—to perform the same operation. It usually takes them from 5 to 8 seconds, and often more.

Although it probably has nothing to do with the tracking-servo speed, the CDP-520ES conveys its message of rapid response to a user from the very beginning. When the OPEN button is touched, the disc drawer quietly opens in about 1 second; it closes for play just as rapidly and smoothly.

Comments

Even if the Sony CDP-520ES did not sound any different (to us) from any other CD player, it certainly sounded fine, measured superbly, and definitely outperformed most others we have tested in the equally important respects of flawless tracking, startlingly smooth and rapid operation, and outstanding ability to resist physical shock. Although you cannot hit it with a hammer while it is playing without causing it to skip a beat, you can subject the top and sides of this player to vigorous slapping and rapping with no effect on the sound. More to the point, unlike many others, it does not require kid-gloves treatment in installation or operation.

We used all the front-panel controls and features of the CDP-520ES, and they worked just as claimed. Despite its deceptive simplicity, this CD player is at least as versatile as any other we have used, and its combination of front-panel and remote-control features makes it more versatile than most. Disheartening as it may be for those people who thrive on negative criticism, we could find nothing about the CDP-520ES that we would wish to see done differently—and certainly not better! No doubt it is in some way unknown to us still not perfect (after all, what is?), and it is quite likely that Sony is even now working to make its fourth-generation players still better and/or less expensive. Until then, however, the CDP-520ES is unquestionably a top contender in a crowded field, besides being a very good value for the money.

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