7-2
7.2
Print Cleanliness
As with any soundtrack, keeping the print clean will give best performance. The Dolby
Digital print format has robust error correction information encoded along with the audio
data, and the DA20 uses a powerful digital error correction technique, allowing the data
to be read perfectly even if scratches and dirt are present. However, best performance
will be obtained if the print is kept clean. Standard film cleaners will provide good
results.
The sound quality of the digital track has properties unlike those of an analog track with
regard to print wear. With any analog track, print wear will degrade quality in a more or
less linear fashion; the more wear, the lower the quality of the sound. With a digital
soundtrack, wear will have no audible effect until the picture quality is degraded beyond
use. At this point, wear may exceed the error correction capabilities of the decoder, and
switching to the analog track will occur.
Quality
Number of plays
ANALOG
DIGITAL
(Sound & Picture)
7.3
Adjustments
Routine adjustments are not required on the DA20 under normal use. Adjustments for
cinema processor type, soundhead delay, surround delay, focus, and film path alignment
are made during installation, and should not be attempted by the operator. Small
adjustments may not affect the sound under most circumstances, and no changes will be
heard, but improper adjustment may reduce the safe operating area within which all
errors can be corrected. Proper test equipment is required. Refer to the DA20 Installation
manual for further information.
Caution: There are no user serviceable parts inside the DA20. To avoid electric shock,
do not attempt any repairs. Refer all servicing to qualified personnel.
