Hi everyone-

My first post to this forum is based on the manual for Samsung's new HL-T5087S DLP HDTV. It claims (page 37) that devices connected to the TV via HDMI will NOT be heard via the TV's digital optical audio out, but only via the analog audio out. The customer service rep at Samsung confirmed this (by looking at the manual himself), and said that starting in 2007 the external audio out for devices connected via HDMI was switched from optical to analog. So I am wondering the following: If HDMI provides digital audio, wouldn't it make sense to maintain that digital audio stream by providing digital output? Unless I'm mistaken, this means that in order to have digital 5.1 sound using the receiver, one must have a separate audio connection from the device in addition to the HDMI out from the device to the TV - somewhat defeats the purpose of having HDMI.

Has anyone tried running digital optical audio to their receiver from their TV, while the TV is set to an HDMI source? Any info would be much appreciated.

Normally, the optical audio output from the TV is just for the TV's internal tuner. If you use an external signal source, that source needs a direct connection to the audio receiver. I don't see that as defeating the purpose of HDMI connections. Using a Toslink connector from the source tuner instead of the TV requires exactly the same amount of cabling. With an HDMI supporting A/V receiver, the idea is one HDMI connection between each source and the A/V receiver and one HDMI cable from the A/V receiver to the TV. HDMI has a ways to go before the concept is adopted and working as well as it will someday though.

I would find it quite useful for the TV to do the switching.... this way the receiver (or pre-amp/decoder) would have one setting for video (DVD, STB, or whatever) rather than having to select the source on the TV and select the source on the receiver. It's just a convenience thing.

I've had a similar experience on my Samsung LCD HDTV.... if the HDMI contains digital stereo audio, the TV will decode the stereo (PCM) audio and pass the signal along to the optical connector. When I switch the HDMI source to DD/DTS the Samsung TV complains that the HDMI audio is not supported and doesn't pass the digital audio signal to the optical out.

I don't quite understand the "HDMI audio not supported" I thought the TV would have a DD decoder built in... even if it only extracted the 2 front channels for the TV speakers...

BTW, my experiments have been with a Samsung DVD player, switching the out audio format from PCM to Bitstream.

DD decoders cost some bucks to make. Also, Dolby gets a royalty for every decoder built. Since a TV is set up for self contained speakers and profit margins are thin while competition is fierce, the extra expense isn't warranted.

DD decoders cost some bucks to make. Also, Dolby gets a royalty for every decoder built. Since a TV is set up for self contained speakers and profit margins are thin while competition is fierce, the extra expense isn't warranted.


But don't they already have DD decoders for off-the-air HDTV?

No. If you use the Toslink output for the OTA tuner to an A/V receiver, the A/V receiver does the DD decoding. The TV only uses PCM for it's built in speakers. There is not much need for a device that only contains stereo speakers to decode a 5.1 bitstream.