Panasonic Prism LX-1000 CD/LD player
Knowing our readers to be quick to respondnegativelywhenever something related to video appears in these audio-dedicated pages (footnote 1), as does John Atkinson that's where the matter would have remained had reports not begun circulating concerning the possible advantages of using videodisc transports for playing back CDs. Theta has chosen just such a devicea Philips-based player modified by Thetaas their dedicated transport (see RH's review in Vol.14 No.11). But the Theta Data is expensive; how, we wondered, would an off-the-shelf combination player perform as either a self-contained CD player or a transport?
Thus the present review, of a combination player from Panasonic, a machine at the top of its manufacturer's line (see Sidebar 1) and Panasonic's first LD player. The main thrust of this review was to evaluate the audio performance of this machine. But I will not ignore its video playback capabilities. The latter, in fact, was the first item on the test schedule. Why? Because, unlike the Theta transport (which retains its video play facilities), this player is promoted as an all-purpose laserdisc player. If it turned out to be an absolute knockout as either a CD player or a transport, of course, that would be significant. But I assumed that anyone purchasing a machine like this would also demand at least acceptable video performance and video sound. Therefore a video check was established as a first hurdle over which this unit should pass before its audio capability would be assessed.
In the US, Panasonic's best audio equipment has always worn the Technics badge. The Prism multi-disc player would, in all likelihood, be a Technics unit if the latter division were in the video business. Like virtually all Japan-sourced video equipment, it has a bazillion features. Most of them, in this case, are useful. Besides the expected ability to play all forms of laserdiscs, the Prism will also automatically play both sides of laser videodiscs in succession; side changing takes only a few secondsfaster than any manual turnover. This isn't just a sop to the couch potato in most of us; many films suffer from any interruption, and no laserdisc plays for over an hour per side, give or take a few minutes.
Most of the controls on the player itself are located on a drop-down panel below the loading drawer; when this panel is closed the front face of the player is clean, user-friendly, andfor videodiscs in any caseprovides the most frequently used controls. This includes a jog-shuttle knob, which operates in either CD or videodisc playback. This control is duplicated on the (full-function) remote, which also includes a number of controls not found on the front of the playerincluding switching between the analog or digital audio tracks of newer videodiscs (which invariably have both).
The back panel of the Prism provides two sets of audio and video output jacks. The digital output is optical only (of the more commonly found Toslink variety, not AT&T). An S-Video output is also provided. There is no RF output for feeding a television which lacks a separate video input. Its designers have evidently assumed (rightly, I think) that the Prism will be used, as a minimum, in a moderately high-end video system, which should have one or more dedicated video inputs.
The LX-1000 also incorporates a digital time-base corrector which helps to minimize horizontal and vertical picture distortion and, according to Panasonic, eliminates jitter (they're talking video jitter here, not jitter in the digital audio signal). The S-Video output separates the Y (luminance) and C (color) signals using a digital comb filter (footnote 2). Digital memory also provides for still and slow-motion capabilities with all videodiscs, not just the less common (and generally more expensive) CAV titles.
The main audio feature of the Prism, which is not really news these days, is the incorporation of MASH (low-bit) conversion for all digital playback. When first introduced about a year and a half ago, however, the Prism was one of the firstif not the firstcombination player to make use of this technology.
The Prism has one other feature I'm not certain I like. If unused for about 30 minutes, it automatically switches off. It's not possible, therefore, to leave it turned on all the timea common audiophile practice.
I found the LX-1000's video performance to be nothing short of outstanding. It was evaluated over a Sony 25" Profeel monitor which, though now ten years old, has held up remarkably well and still provides a sharp, bright, well-defined picture. Which is exactly what the Panasonic is capable of sending to it, given the best program material. The Prism's picture, while it has a shade less subjective snap and crispness than the similarly priced Pioneer CLD-3090's, has more fully saturated colors and less (and very low) video noise.
Our first sample of the Prism, however, did exhibit a troublesome problem with certain CAV discs (footnote 3). The discs would play nearly to the end of the side, then the picture would freeze up or otherwise jump and jitter and fail to make forward progress. This happened with Reference Recordings' Video Standard test disc, and Flyers, a Philips disc which is a transfer of an original IMAX presentation. Sides 3 and 4 of the Criterion CAV version of Close Encounters of the Third Kind also gave some problems; side 4, in particular, had a nasty breakup near the end, which also resulted in rather alarming sputtering and transients from the audio track.
At this point I requested and received a second sample of the Prism to determine if the above problems were player-related. All discs tried played properly on the second sample except those from Close Encounters. The problem on side 3 was limited to a single minor glitch where the player entered pause (and released normally on pressing Play). The breakup on side 4, though, was almost as severe as on the first sample. However, a glitch also appeared at the same point (near the arrival of the mother shipnot exactly an insignificant scene) when played back on an old Pioneer LD-1100. The problem was, apparently, in the disc. A number of other CAV discs played without difficulty. In the one report I've seen of a similar problem with the LX-1000 which actually could be attributed to the player itself, the problem was fixed by a Panasonic service center with a minor adjustment.
Two other reports of which I'm aware, including a review in another magazine, have criticized the LX-1000 for having "herringbone"-patterned video noise in its picture. I only encountered an artifact anything at all like this in two isolated spots on two discsof a large number sampledand then it only affected small and specific parts of the picture for a few seconds; in my opinion this was in the disc itself. A full-screen herringbone pattern never occurred on either of our LX-1000s, but since others have experienced it, it may be a possible problem in some samples.
The reference audio system used in the CD evaluations consisted of the Rowland Consummate preamplifier, Krell KSA-250 power amplifier, and Apogee Centaur Major loudspeakers. (My review of these loudspeakers will appear in the April 1992 issue.) Interconnects were AudioQuest Lapis (the next to the latest generation) from CD player to preamplifier, and Cardas Hexlink from preamplifier to power amplifier.
As a preface here, I would like to make only one comment on the sound of the LX-1000 with respect to its playback of video discs. It never gave me any reason to complain, given the limitations inherent in most such program material, and indeed it was frequently first-rate, again given the program material. But I did notice that I subtly but consistently preferred the sound of the analog soundtracks over that of the digital from the same discs. While the analog did appear to be very slightly louder much of the timewhich certainly may have tipped the subjective scales in its favorI don't believe that was the only difference I was hearing. The analog tracks almost invariably sounded more open and airy, the digital just a bit canned and closed-in, in comparison.
Footnote 1: Though usually only when the product is perceived to be video only; ie, monitors. We will continue to cover sound-for-video topics and products on occasion, such as the Snell/Lexicon home THX system which JGH is currently auditioning.
Footnote 2: This type of output is of less significance in a laserdisc player than in an S-VHS video recorder. In the latter, the two signals are recorded separately; keeping them separate all the way to the monitor circuits (and eliminating the need for the latter to separate them) may enhance picture quality. On a videodisc, the two signals are already combined in the recording. They must be separated on playback at some point, but whether this is done in the videodisc player or in the monitor is rather irrelevant. If your videodisc player provides better separation circuits than those in the monitor, you may get better picture quality by using the S-video outputs. If it doesn't, you won't. All of this presumes, of course, that your monitor also has an S-Video input. Some, like mine, don't; I used the standard video outputs in my video assessment of the Panasonic player.
Footnote 3: CAV stands for constant angular velocity, often referred to as standard play on the disc jacket. The more common "extended play" discs are CLV, or constant linear velocity. CAV discs provide 30 minutes per side and rotate at a constant 1800rpm. Until the advent of players with digital field memory, only CAV discs would provide slow motion, freeze-frame, and other so-called special effects.