Handling Compact Discs - NAD 523 Manuel D'installation

The display's track Calendar will also show which
tracks of the disc currently playing have been pro-
grammed for Memory play. As each track is played or
skipped past its Calendar number is blanked out. (only
for the first 20 tracks of that disc, as the Calendar dis-
plays up to a maximum of 20 tracks).
If you make an error during programming you must
press MEMORY to clear the current program, press
MEMORY again to restart and enter your track listing
from the beginning.
NOTE: If you engage the Memory mode while play-
ing a disc, the current track will be included as the first
entry in the stored program. As long as MEMORY is
shown in the display you can add further entries to the
stored track list. Simply enter the new Disc Select and
Track Select numbers as above.
As long as the MEMORY indicator remains illumi-
nated, only the stored Memory program can be played.
If you want to play a track not included in the program,
you must either add it to the program (as above) or exit
from the program mode by pressing MEMORY on the
remote control. Exiting will delete the stored track list
from the player's memory.
C. CLEAR.
With the CLEAR button you can delete the last
selected entry from Memory play; press the CLEAR
button once. Every successive time the CLEAR button
is pressed, a Memory Play entry is deleted. Once the
CLEAR button is pressed, the display will show for two
seconds the current amount of programmed selections
for Memory Play.
D. RANDOM.
Engages and disengages random track selection.
The player will play each track of each CD in a random
sequence.
Random can be combined with Repeat and/or
Memory play.
NOTE: Random is also disengaged if the drawer is
opened.
MAINTENANCE.
At periodic intervals, open the disc drawer and wipe it
with a damp cloth to remove any loose dust.
DISC LOADING PROBLEMS
Whenever the carousel tray revolves to select a dif-
ferent disc, the optical pickup automatically scans a
"table of contents" track at the beginning of the disc,
containing coded information about its playing time and
the location of each track.
If you accidentally place a disc in the drawer upside
down, or if a disc fails to load properly into the playing
mechanism, the pickup will be unable to find the con-
tents track. After a few seconds of searching, the corre-
sponding Disc No. in the display will disappear and the
player will move on to the next disc. If this happens
open the drawer and re-insert the disc.

HANDLING COMPACT DISCS

Handle Compact Discs with care. The playback of a
disc will not be impaired by small dust particles, a few
light fingerprints, or slight scratches. But large scratch-
es, or a thick layer of oily fingerprints, can prevent the
player from tracking the disc. (Incidentally, although the
tracking laser "plays" the disc through its clear side, the
actual data surface is embedded directly beneath the
label, protected only by a very thin coating of lacquer.
So a scratch that cuts through the label may damage
the disc more than a similar scratch on the transparent
"playing" surface. Thus you should treat both surfaces
of the disc with care.)
Severe scratches or fingerprints may cause the play-
er to mis-track (skipping ahead, or repeating the same
passage). Less severe damage may produce very brief
bursts of high-frequency noise. Compact discs should
not be abused or handled carelessly.
For best results, grasp the disc only by its edges.
Another safe method is to put a finger in the centre
hole, using the thumb at the edge to hold the disc
steady.
Each disc should be kept in its protective storage
case when not in use. To open the standard Philips-
type plastic CD case, grasp the top and bottom of the
case with the fingers and thumb of the left hand; then
grasp the left and right edges of the case with the fin-
gers and thumb of the right hand, and pull the case
open with the right thumb.
The disc is held in place within the case by an expan-
sion hub in its centre hole. To remove the disc, press
the hub with a finger to release the disc, then lift it out
by gripping its edges between the fingers and thumb.
To replace the disc in the case, simply align its centre
hole with the hub and press the disc onto the hub.
Soiled discs may be cleaned by wiping with a soft
cloth, either dry or moistened with water. Do NOT use
conventional LP record-cleaning products (cleaning
solutions, sprays, treated cloths, or anti-static prepara-
tions), nor any kind of chemical solvent (alcohol, ben-
zene, etc.). A severely soiled disc may be washed in a
warm-water spray, possibly with a small amount of a
mild kitchen detergent added, and then wiped dry with
a clean, soft towel.
When cleaning the disc, use only RADIAL strokes
(from centre to edge). Never use a circular wiping
motion like that used for cleaning ordinary LP records,
because in wiping the disc there is a risk of scratching
it. A radial scratch will do the least harm because it
affects only a small portion of each circular data track,
which can be fully compensated by the player's error-
correction circuits. But a circular scratch that follows a
data track may damage such a long continuous seg-
ment of data that it cannot be corrected.
ABOUT THE LASER
The Compact Disc player uses a solid-state semi-
conductor diode laser, mounted on a tracking servo
mechanism, to play the disc. The laser illuminates the
track of microscopic pits representing the digital data
bits, while photo-diodes detect the reflected illumination
from the disc and convert it into an electronic signal
which is then decoded to recover the musical waveform
in each stereo channel.
GB
NAD
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