Audio - Philips L05HD Training Manual

Audio (Figure 12)
All audio processing and control is performed by the Hercules IC 7200 located on the main
board.
Audio is included in the HDMI bit-stream. Digital audio from 7002 is fed to IC 7011, Audio
DAC. Audio from 7011 is fed to IC 7050, switch, which has only one input since the second
input is not used in the HD version. The output of 7050 is fed to the Hercules IC located on
the Main board. Audio for the CVI input should be inserted into AV1. Audio is output from the
Hercules on Pins 68 and 69 to the Audio Amplifier, IC 7990. This is a two channel 20 watt
amplifier.
Audio output
Main audio is output on Pins 68 and 69 and fed to the audio amplifier 7990. The audio ampli-
fier is a dual 10 watt amplifier. It is powered by the +VAUDIO and -VAUDIO supplies. These
are +16 and -16 volts. To mute the amplifier, the VOL_MUTE line goes Low switching tran-
sistor 7992 Off switching transistor 7991 On. The output of the amplifier is fed to the Side
Jack panel.
Monitor audio is output on Pins 66 and 67 of 7200. These outputs are muted by the
STBY_CONT and POWER DOWN lines. The POWER DOWN line is High during normal
operation. As the set powers off, this line goes Low, switching 7993 Off. Transistor 7104
then switches On to mute the output. The STBY_CONT line goes High when the set is
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FIGURE 12 - AUDIO BLOCK