Kenwood DP-1100B CD-player Review

Kenwood DP-1100B
Kenwood DP-1100B

Kenwood's second-generation digital Compact Disc player, the DP-1100B, offers an impressive array of performance and operating features in a low-profile package. It comes with a compact, battery-operated, infrared remote-control unit that not only duplicates the player's extensive front-panel control functions but also has a feature, called m-scan, that automatically samples the first 10 seconds of each programmed selection.

Many second-generation CD players have special provisions for improved tracking ability with damaged or defective discs, and the DP-1100B is no exception. Its Optimum Servo Control circuitry is intended to reconcile two conflicting design goals for the servo-tracking system that makes the player's laser beam follow the spiral pattern of recorded information embedded in a Compact Disc. A high-gain servo tracking system is desirable to increase a player's resistance to external vibration and shocks. But a high-gain system could also cause a player to be unduly sensitive to minor defects or 1 damage on the discs themselves.

Kenwood's Optimum Servo Control is normally a high-gain system, but internal circuits sense the first signs of a potentially "untrackable" disc defect and temporarily reduce the servo gain so that the laser does not become "de-tracked" as the defect passes. Since damages and defects usually extend over several revolutions of a disc, the system also stores the location of the defect, and during the next revolution the servo gain is again lowered at the same point in anticipation of the passing damage.

The DP-1100B is finished in black and measures about 17-5/16 x 12-3/16 x 3-1/2 inches. It weighs about 15 pounds. Price: $899.

LAB TESTS

The performance of the Kenwood DP-1100B, like that of every other correctly functioning CD player we have tested, was superb, usually taxing the abilities of our test instruments to their utmost. The only departure from near-ideal audio performance (and it was a trivial one) was a difference in the left- and right-channel output levels of just over 0.5 dB. This could easily have been a characteristic of our test sample alone. Besides, the inherent unbalance in just about any other program source, to say nothing of the rest of a stereo system, is likely to be at least this great.

There was a moderately high phase shift between the outputs of the two channels at the highest audio frequencies, less than a few degrees at 1,000 Hz and increasing to 43 degrees at 10,000 Hz and 75 degrees at 20,000 Hz. This phase shift has no audible significance that we are aware of. It merely suggests that a single digital-to-analog-converter integrated circuit is being switched to supply both channels, an alternative to using a separate converter for each channel.

In our tests, the DP-1100B did a nearly perfect job of tracking the calibrated defects on the Philips TS4A test disc, failing only to track the largest (800-micrometer) black dot painted on the disc's surface. And it was easily the best CD player we have yet tested in terms of immunity to external shock and vibration. Not only did it ignore moderate blows to its external surfaces (any of which would have caused a phono stylus to leave the groove and jump about), but it actually required a strong blow, delivered with genuine effort, to cause a momentary dropout of the program. This is in striking contrast to most of the first-generation CD players we tested last year, which required rather careful handling to avoid such effects. Most CD players, however, are fairly resistant to common feedback effects.

We judge the cueing accuracy of a CD player by how effectively it handles the transition from Track 17 to Track 18 of the Philips TS4 sampler disc. There is no blank space between these two tracks, and the playback goes directly from the end of No. 17 to the vocal beginning of No. 18. Most players detectably clip the first syllable of Track 18, some lose much of the first word, and a very few make the transition perfectly. The DP-1100B was almost perfect, rating an A- in this respect. Sometimes we could detect the loss of what we would guess to be a few milliseconds of Track 18, but on other tests the transition was perfect.