Probably answered a million times, but here goes:

My HDTV will not pass Dolby 5.1, so an HDMI connection to the TV will only output 2-channel audio. I also believe the HDMI protocol is such that the DVR will recognize this and will only put 2-channel audio out on the HDMI line. So, I currently use optical audio out from the DVR directly to the receiver, and component video from the DVR to the TV -works fine. My question: If I go to HDMI from the DVR to the TV to gain the video advantage, will the DVR continue to output Dolby 5.1 on its optical audio output or will it also downmix the optical output to 2-channel?

Thanx,
SrPicman

The advantage to HDMI is the single smaller cable. There is not any inherent improvement in PQ. If you see an improvement it will be slight and due to your hardware not the cable.

My moto HDDVR will outputs 5.1 via optical/SPDIF without regard to the video output. Others may differ.

Probably your DVR has a setting that will tell it to output DD 5.1 over its digital audio connector, regardless of what the HDMI interface says to it. My last two DVRs (HR20, SA8300HD) have worked that way. But it's no sure thing. I had a cable DVR about 3 years ago that would not output multichannel audio over digital audio when HDMI connected to the TV was telling it that the TV could only handle stereo. That, of course, was a bug.

Probably your DVR has a setting that will tell it to output DD 5.1 over its digital audio connector, regardless of what the HDMI interface says to it. My last two DVRs (HR20, SA8300HD) have worked that way. But it's no sure thing. I had a cable DVR about 3 years ago that would not output multichannel audio over digital audio when HDMI connected to the TV was telling it that the TV could only handle stereo. That, of course, was a bug.

GregLee,

Thanks for the quick and clear reply. My DVR is a SA8300HD (TV is Pioneer Pro 1130 Elite) and there is a Menu Audio selection with options for "HDMI" or "DolbyDigital", so I expect you're correct that the optical Audio out can be independent of HDMI. I do not expect a significant PQ improvement with HDMI, but since it is digital vs. the Component analog, I'd think it wouldn't be worse.
SrPicman