The incoming digital information may have slight inaccuracies in
the timing. An extremely stable and accurate clock in the DAC20
synchronises with the incoming data and ensures that any timing
errors are minimised, thus reducing ‘jitter’.
The LED on the front panel marked
lock
shows when the clock is
properly synchronised. This may take a second or so depending
on the type of signal source.
If the timing of the incoming data is very erratic, the clock in
the DAC20 may be unable to synchronise. In that case, the LED
will go out but the music will still be played using timing from
the recording
(1)
.
Some recordings are made using a noise reduction technique
called pre-emphasis.
The DAC20 automatically recognises recordings with pre-
emphasis and applies de-emphasis to take advantage of the
noise reduction
(1)
. The LED on the front panel marked
demp
(short
for de-emphasis) illuminates when a recording with pre-emphasis
is being played.
automatic
de-emphasis
detection
internal clock
synchronisation
18
19
jitter reduction
de-emphasis
1. Pre-emphasis is used in some recordings to improve the potential playback
quality but it is not often used
1. The most likely cause of erratic data is a fault in the signal source equipment or
connecting cable, either of which may need servicing. Please contact your
retailer if you have problems with synchronisation
lock
demp
GRA00046.1-[CA]DAC20 13/03/01 10:06 Page 19
