The high pitched sound comes through the receiver?
Do you have the television speakers set to external, or is the sound coming from the TV? If it's through the Amp, it may be a signal that the AMP doesn't recognize, and may be adjusted by changing the audio signal to 5.1 if 5.1 is being broadcast.
I recently bought the LED 8000 series 55" TV and it's the best I've had for picture quality. However, I do have an issue with the sound.
I have the following connections:
Wall antenna connected to Panasonic DMR350 Digital recorder.
HDMI connection from Digital Recorder to TV.
HDMI connection from PS3 to TV.
Panasonic VCR connected to TV through component jack.
TV optical out to the optical connection of a Sansui Digital Intigrated Amp, which is connected to Jamo 507 Floor speakers.
The PS3 (through which I play Blu Ray DVDs), the VCR and the DVD recorder all work with the amplifier - no issue with picture & sound. Also, if i watch TV through the DVD recorder there is no issue for all channels that is played through the amplifier.
However, If I just want to watch TV through the amplifier, the sound only works for the Analogue & Digital channels, but not for the HD channels...like Ten's sports channel (11), and the ABC/SBS/Seven & Nine's HD channels. There is is high pitched crackling sound for these channels and it is beyond me to figuer out why?