Panasonic EURO 4 Chassis, Техническое руководство

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20.4.4.Spartial Effects
The Spartial effects depend upon the source signal,
if the source signal is mono then a Pesudo stereo
effect can be used. However if the source signal is
stereo then Stereo ambience can be used.
To switch on and off the spartial effects, the OSD
menu has to be accessed.
:
Pseudo Stereo Effect.
To achieve pesudo stereo a mono signal is split into
different frequency ranges, these frequencies are
then fed to both channels for further processing.
The signal applied to the left channel runs through a
band pass filter, whilst the right channel is fed to an
adder circuit, here the left channel in anti-phase to the
right channel are added together, for the resulting
frequency response
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Stereo Ambience
Ambience represents an important acoustic
improvement in TV sets due to a narrow speaker
range. Ambience is produced at this stage by the
merging of the middle frequencies of one audio
channel in anti- phase to the second audio channel
and vice versa.
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Once the audio signals have undergone the various
bass, treble adjustments etc. the signals are fed to
the volume and balance control circuits. Once again
the various adjustments are carried out via the
remote control with the adjustment settings being
displayed on screen, the signals are then buffered
and output via pins 24 and 25 of the MSP3410
IC2101 .
The signals output from the MSP3410 IC2101 are
then fed via transistors Q2102 and Q2103 . from
here the signals are then fed to the input of IC251
audio output IC.
20.4.5.Stereo Headphone Output path
Headphone output signals are taken from the
loudspeaker signal out which is routed via the
headphone terminal. This means that when the
headphones are connected the TV speakers are
switched off.
Dolby Pro Logic models however use a separate
output for the headphone terminals which provides
independent control for bass, treble and volume.
The audio output for the headphone terminal being
pins 21 and 22 of the MSP
IC2101 , which on
standard models are used for phono out.
20.4.6.Phono Output
The audio signal used for the phono output is fed
from pins 21 and 22 and fed via two buffer
transistors
Q2302 , Q2304 before being fed to the
phono terminal JK2301.
These output terminals pins 21 and 22 of the MSP
IC2101 are for Dolby Pro Logic models used to
provide a separate output for the headphone which
is independently controlled for bass, treble and
volume. (for headphone processing refer to section
24.7.)
20.4.7.A.V. Scart Output
Signals selected for outputing to the 21pin scart
terminals, are fed via a stereo separation circuit as in
the loudspeaker path, however there are no bass,
treble, spatial effects or balance controls, just a
volume control circuit. The audio signals output from
the MSP3410
IC2101 via pins 27/28 and 30/31 are
then fed to AV1 / AV2 21 pin scart terminals.