26
OPERATION
In addition to the
Bitstream Indicators
, the
AVR 2550 features a set of unique channel input
indicators that tell you how many channels of
digital information are being received and if the
digital signal is interrupted.
These indicators are the L/C/R/SL/SR/LFE letters
that are inside the center boxes of the
Speaker/Channel Input Indicators
P
in the
front panel
Main Information Display
Ú
.
When a standard analog stereo or matrix sur-
round signal is in use, only the “L” and “R” indi-
cators will light, as analog signals have only left
and right channels, respectively, even surround
recordings, carry surround information on the left
and right channels only.
Digital signals, however, may have one to six sep-
arate channels, depending on the program mate-
rial, the method of transmission and the way in
which it was encoded. When a digital signal is
playing, the letters in these indicators will light in
response to the specific signal being received. It
is important to note that although Dolby Digital,
for example, is referred to as a “5.1” system, not
all Dolby Digital DVD or audio tracks selected on
DVD or other Dolby Digital programs are encod-
ed for 5.1. Thus, it is sometimes normal for a
DVD with a Dolby Digital soundtrack to trigger
e.g. only the “L” and “R” indicators.
NOTE
: Many DVD discs are recorded with both
“5.1” and “2.0” versions of the same sound-
track, the ”2.0” version often is used with other
languages. When playing a DVD, always be cer-
tain to check the type of material on the disc.
Most discs show this information in the form of a
listing or icon on the back of the disc jacket.
When a disc does offer multiple soundtrack
choices you may have to make some adjustments
to your DVD player (usually with the “Audio
Select” button or in a menu screen on the disc)
to send a full 5.1 feed to the AVR 2550 or to
select the appropriate audio track and thus lan-
guage (”2.0” audio tracks can be played with all
Pro Logic II or Vmax modes, see "Dolby Digital"
on page 26). It is also possible for the type of
signal feed to change during the course of a DVD
playback. In some cases the previews of special
material will only be recorded in 2.0 audio, while
the main feature is available in 5.1 audio. As
long as your DVD player is set for 6-channel out-
put, the AVR 2550 will automatically sense
changes to the bitstream and channel count and
reflect them in these indicators.
The letters used by the
Speaker/Channel Input
Indicators
P
also flash to indicate when a bit-
stream has been interrupted. This will happen
when a digital input source is selected before the
playback starts, or when a digital source such as
a DVD is put into a Pause mode. The flashing
indicators remind you that the playback has
stopped due to the absence of a digital signal
and not through any fault of the AVR. This is nor-
mal, and the digital playback will resume once
the playback is started again.
Night Mode
A special feature of Dolby Digital is the Night
mode, which enables Dolby Digital input sources
to be played back with full digital intelligibilty
while reducing the maximum peak level and lift-
ing the low levels by
1
/
4
to
1
/
3
. This prevents
abruptly loud transitions from disturbing others
without reducing the impact of the digital source.
The Night mode is available only when Dolby
Digital mode is selected.
The Night mode may be engaged when a Dolby
Digital DVD is playing by pressing the
Night
Button
A
on the remote. Next, press the
⁄
/
¤
buttons
C
to select either the middle range or
full compression versions of the Night mode. To
turn the Night mode off, press the
⁄
/
¤
buttons
C
until the message in the lower third of the
video display and the
Main Information
Display
M
reads
D-R OFF
. When the Night
mode is active, the
Night Mode Indicator
O
will also illuminate.
The Night mode may also be selected to always be
on at either level of compression as soon as the
Dolby Digital mode is turned on using the options
in the Night Mode settings. See page 20 for infor-
mation on using this option.
IMPORTANT NOTES ON DIGITAL PLAYBACK:
1. When the digital playback source is stopped,
or in a pause, fast forward or chapter search
mode, the digital audio data will momentarily
stop, and the channel position letters inside the
Speaker/Channel Indicators
P
will flash.
This is normal and does not indicate a problem
with either the AVR 2550 or the source machine.
The AVR 2550 will return to digital playback as
soon as the data is available and when the
machine is in a standard play mode.
2. Although the AVR 2550 will decode virtually all
DVD movies, CDs and HDTV sources, it is possible
that some future digital sources may not be com-
patible with the AVR 2550.
3. Note that not all digitally encoded programs
and not all audio tracks on a DVD contain full
5.1-channel audio. Consult the program guide
that accompanies the DVD or laser disc to deter-
mine which type of audio has been recorded on
the disc. The AVR 2550 will automatically sense
the type of digital surround encoding used, indi-
cate it in the
Bitstream Indicators
A
and
Channel Input Indicators
P
and adjust to
accommodate it.
4. When a Dolby Digital or DTS source is playing,
you normally may not be able to select some of
the analog surround modes such as Dolby Pro
Logic II, Dolby 3 Stereo, Hall, Theater, 5CH Stereo
or Logic 7, except with special audio tracks
(see indication ”Dolby Digital” on previous page)
or data format selected (see ”PCM” on previous
page).
5. When a Dolby Digital or DTS source is playing,
it is not possible to make an analog recording
using the
Tape
1
or
Video 1
4
record out-
puts, if the source is connected to any digital
input of the AVR 2550 only. But the analog two
channel signal of that source, the ”Downmix” to
Stereo or Dolby Surround, can be recorded by
connecting its analog audio outputs to the
appropriate analog inputs (e.g. DVD) of the AVR
2550, even if the digital input of the AVR 2550
remains selected. Additionally, the digital signals
will be passed through to the
Digital Audio
Outputs
8
.
Tape Recording
In normal operation, the audio or video source
selected for listening through the AVR 2550 is
sent to the record outputs. This means that any
program you are watching or listening to may be
recorded simply by placing machines connected
to the outputs for
Tape Outputs
1
or
Video 1
Outputs
4I
in the record mode.
When a digital audio recorder is connected to
any of the
Digital Audio Outputs
8
, you are
able to record the digital signal using a CD-R,
MiniDisc or other digital recording system.
Note that all digital signals will be passed
through to both, coaxial and optical, digital out-
puts simultanously, no matter which kind of digi-
tal input was selected.
NOTES:
• The AVR 2550 can convert an analog input to a
digital signal. This way the analog or digital
signals can be recorded on a CD-R via the digital
output. Note that the change of format (eg from
Dolby Digital to PCM or vice versa) is not
possible.
In additon, the digital recorder must be compatible
with the output signal. For example, the PCM digi-
tal output from a CD player may be recorded on a
CD-R or MiniDisc, but Dolby Digital or DTS signals
may not.
• To make an analog recording of a Dolby Digital
or DTS source is not possible, if the source is con-
nected to a digital input of the AVR 2550 only.
But the analog two channel signal of that source
can be recorded (see item 5, ”Important Notes
on Digital Playback” above).
Operation
