Linear PCM is standard two-channel output (CD's use this). The Dolby Digital setting allows for multi-channel (5.1, etc.) output. You must use a digital connection (coax or optical) to the receive/processor to decode the multi-channel signal. Basically the Dolby Digital setting is best as long as you have the appropriate decoding equipment (DD receiver/pre-pro). Good luck.
I have the motorola box and have found that it doesn't matter what you have it set for, both the rca and SPDIF outputs seem to work all the time. Whatever equipment you have connected to the box should work either way.
The key is to be certain that your receiver can decode DD. Unless its pretty old, that is almost a given, but if it did NOT handle DD, you would likely hear some pretty nasty sounding digital hash.
Don't know how much content you will get from your cable system in DD, but if there is any, its always fun to listen to.
I am a DirectTV guy, and I get a fair amount of HBO in DD, plus HDNet, Discovery HD. Also a fair amount of ABC HD programming as well via OTA.
Brian, Can you believe that with all the ABC programming available in DD, my local affiliate WJLA in Washington DC (not exactly a small market) does not broadcast the signal? I only get standard surround signal. I have checked on the net to make sure it wasn't a shortcoming in my equipment or the cable provider. Sure enough, the station just doesn't offer it!
I don't think your situation is all that uncommon. My local CBS affiliate has been HD for going on two years, but they lack the equipment to pass along CBS' DD feed.
And we got word recently that our city is one of the trial cities for USDTV. Our UPN affilate is leasing their extra bandwidth to USDTV, such that it appears they will not have enough to pass along UPN's HD content.
Nahh, I think they are DD. Our local station engineer is a really good guy, and he has commented that they just don't have the budget to buy the required gear.
Not if the FCC was doing their job. The bandwidth given to them(UPN)was not intended for them to lease out, but to provide a digital channel, and if the guidelines were made with some foresight and the public's best interest in mind, an HD channel. That's ridiculous what they're doing.
David "I want my HDTV" and "Preaching to the Choir" Judah