Pioneer PD-75 CD-player Review

Pioneer's top CD player, the PD-75, is a new addition to the company’s Elite series of audio components. Like other Pioneer Elite products, the PD-75 is ruggedly built and tastefully styled, and it embodies a number of unusual electrical and mechanical design features that are claimed to provide a closer approach to ideal performance than has previously been available in a CD player.

For maximum isolation between the player’s analog and digital sections, their power supplies (including power transformers) are completely separate. A new Pulse Flow 1-bit digital-to-analog (D/A) converter circuit developed by Pioneer is said to be simpler than the 1-bit systems used by other manufacturers and to exhibit lower noise and distortion and less phase shift.

The mechanical aspects of the PD-75 have received equal attention. The heavy steel chassis and cabinet, with a multilayered honeycomb-plastic base, is supported on large vibration-isolating feet. A unique Stable Platter drive mechanism is said to effectively eliminate disc wobble by firmly clamping the disc to a rotating turntable, with only a thin rubber pad separating the two. Unlike almost all other CD players, the PD-75 requires the disc to be inserted with the label side down; its drive motor, disc clamp, and laser pickup are located above the disc.

The rotating metal platter is supported on isolating springs from the frame of the drive mechanism. The Hall-effect motor has no brushes or other mechanical contacts associated with its rotor, and it provides approximately five times the starting torque of conventional CD player motors. Its highly rigid shaft, more than twice the diameter of those used in conventional motors, is claimed to provide a smoother, more constant disc rotation. The combined rotating mass, about three times that of conventional CD mechanisms, further enhances the smoothness of the disc rotation. The entire motor assembly is isolated from the drive frame on separate springs.

After a disc is loaded, the motor assembly descends to place its oversize clamper on the disc, exerting four times the force used in previous Pioneer players. Because of the support afforded by the Stable Platter disc drive, this added pressure can be applied without warping or otherwise affecting the disc. The principal benefit of the design is said to be the virtual elimination of disc wobble, which Pioneer says enables more accurate reading of the digital program information. Pioneer claims another advantage as well: Any dust particles within the machine will be drawn by gravity away from the critical laser lens, rather than toward it as in more conventional designs.

Pioneer's laser measurements and FFT analysis comparing the rotation and vibration patterns of a CD in a conventional disc drive and in the Stable Platter disc drive clearly show a dramatic reduction of vibration frequencies and amplitudes with the Stable Platter design.

The PD-75 is a highly versatile player, yet it is simple to operate. The disc drawer, in the lower center portion of the panel, extends at the touch of a button and retracts at a second touch after the disc has been loaded. Like the drawer button, the play and pause controls are large and well marked. The only other operating controls on the panel are the stop and track-skipping buttons. To the left of the disc drawer are three buttons that activate the digital and analog outputs on the rear apron (individually or together), switch the display on and off, and turn the power on and off.

Above the disc drawer is the display, which normally shows, in large orange numerals, the current track and index numbers and the elapsed time on the track. Other information, such as the status of programming and repeat modes, appears in small letters.

Most of the Pioneer PD-75’s functions are accessible only from its infrared remote control. In addition to duplicating the few front-panel operating controls (including the drawer open/close button), the remote offers a two-speed fast-search function (with sound), index selection, random play, and repeat of the current track, entire disc, or selected sequence of tracks.

A numerical keypad on the remote control provides direct access to any track up to No. 99. Any or all tracks on a disc, to a maximum of twenty-four, can be programmed to play in any sequence. Pauses can also be programmed into the sequence so that playback will halt at desired points and resume when the pause button is pressed. Other buttons are used to check the programmed sequence and to clear the program memory. Unlike most other programmable CD players, the PD-75 has a nonvolatile memory that retains the program for as long as several days after power is removed and resumes playback from where it left off when the player is next turned on. The clear button on the remote, however, will permanently remove any or all programmed steps.

Finally, the time button steps the display from elapsed time on the current track to remaining time on the current track, remaining time on the disc, and total playback time on the disc. The PD-75 can also display the playing time of any track (up to No. 30) if you press the track-selector button in stop mode, and it can start play from any desired point on a track or disc reached by using the scanning buttons in stop mode.

The PD-75’s rear apron has conventional analog audio outputs as well as both optical and coaxial digital outputs. There are also separate balanced analog outputs (using Cannon connectors) for professional recording and broadcast applications. A jack can connect the PD-75 to a compatible Pioneer cassette deck for synchronized recording, and another jack can connect the player to a Pioneer SR series amplifier so its remote control can operate the CD player as well.

The Pioneer PD-75 measures 18 inches wide (including the furnished wood-grain side panels), 14 inches deep (including the balanced-output rear extension to the chassis), and 5-1/8 inches high. It is finished in glossy black, with contrasting gold markings, and weighs 26 pounds. Price: $1,200.

Lab Tests

The maximum (0-dB) output voltage from the Pioneer PD-75 was 2.57 volts, slightly higher than the normal 2-volt standard. With most amplifiers, this poses no problem, although there are a few receivers whose electronic volume-control circuits could be overloaded by that much signal.

The player’s frequency response was almost literally ruler-flat, within + 0, -0.09 dB from below 20 Hz up to 20,000 Hz. Interchannel phase shift varied linearly from zero at 5 Hz to 1.1 degrees at 20,000 Hz. Channel separation was excellent, varying from slightly more than 100 dB at 100 Hz to just slightly less than 100 dB at 20,000 Hz. Dynamic range (EIAJ) was 95.6 dB, and the internal emphasis-correction response error was less than 0.16 dB. Frequency error was a barely detectable + 0.0008 percent.

Total harmonic distortion plus noise (THD + N) at 1,000 Hz was about 0.0035 percent at levels from 0 to —70 dB. At a 0-dB level, it was less than 0.004 percent from 20 to 20,000 Hz. We also measured the harmonic distortion alone (without noise) using the digital signal processing capability of our Audio Precision test equipment. At a 0-dB level, most harmonics from the third to the fifteenth were barely measurable, mostly around -100 dB, resulting in a THD reading of only 0.0023 percent ( — 92.7 dB).

Since the most striking performance advantage of a 1-bit D/A converter, compared with most conventional multibit converters, is excellent linearity at low signal levels, we measured the PD-75’s departure from an ideal output signal at recorded levels from -70 dB to -90 dB. At -70 dB, the error was essentially zero, and it reached a maximum of +0.3 dB at -80 dB; at -90 dB, the error was a mere 0.09 dB. These results, typical of good 1-bit converters, surpass those from nearly all conventional multibit converters.

The A-weighted noise level, referred to a 0-dB output, was -117.5 dB. The reading did not change when we shut off the display, which is often said to contribute significant noise to the audio output. A spectrum analysis of the noise also showed no difference over the 20- to 20,000-Hz range when the display was switched on and off.

The player’s laser tracking was extremely fast: It slewed from Track 1 to Track 15 of the Philips TS4 test disc in less than 1 second (too fast to measure with a stopwatch). Tracking ability was good though not exceptional. The PD-75 played the 1,000-micrometer signal interruption on the Pierre Verany #2 test disc with no audible mistracking and emitted only a single barely audible “tick” on the transition between the 1,250-micrometer and 1,500-micrometer interruptions. At the 2,000-micrometer interruption, the player clearly mistracked (as do virtually all others we have tested).

In view of Pioneer’s claims to having achieved a stable disc platform, we were curious to see how the PD-75 stood up under impact. On our test bench (a sturdy, heavy platform), it took a very hard slap on one side of the player to induce a momentary signal interruption. No amount of fist-pounding on the top of the player caused any audible effect (I was limited only by concern for damage to the top plate or, worse yet, my wrist!).

Comments

Clearly, the Pioneer PD-75 is an exceptional CD player. Given the inherent performance capabilities of the CD system, it is often difficult to measure, let alone hear, the benefits of the design refinements incorporated in some of the top models. In all honesty, we could not positively identify any audible benefits of the PD-75’s special construction and circuitry, but it certainly sounded at least as good as any other player we have used.

There was no doubt about its bulletproof construction, however. It is the first home CD player we have tested that could not be made to mistrack when we pounded on its top cover, even with unreasonable force, while it was sitting on a rigid, massive surface. When it was placed on a relatively flexible steel shelf, it could be made to mistrack with moderate blows, but the same applies to any other CD player we have used, no matter how immune to impact it was on the test bench.

The PD-75’s operating simplicity is one of its major attractions. There is no need to search through a panel full of buttons to enjoy the benefits of its versatility. Not all of its special features are obvious from the front panel (or even the remote control), but the manual is clear and complete.

By now, most audiophiles are well aware of the degree to which CD player measurements transcend those of many other audio components. Our measurements of the PD-75 further emphasize those differences. Without an impractical item-by-item comparison against test data from other players, we cannot say in which respects the PD-75 is “the best,” but few of its measurements were less than outstanding. And the more we used it, the more its versatility became apparent. The upside-down disc loading arrangement seemed strange at first, but it soon became perfectly natural.

We never had occasion to use either the balanced outputs or the digital outputs, but it would be hard to imagine any situation in which using the digital outputs and an outboard D/A converter would provide an improvement on the sound quality delivered by the player’s internal 1-bit converters. All in all, the Pioneer PD-75 is a handsome, versatile, and satisfying component. Truly “Elite”!

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