Help: Digital Optical output making nothing but noise...

[Doctaspawk]

I need advice as to why my audio receiver, an RCA RT2770(perfectly capable of 5.1 digital output)only makes loud hissing/popping noise when used in conjunction with my PC via optical 5.1 output or my Xbox 360(same output). I used to own the previous model which was the 2760, the only differences are that the 2760 had usb input and only 1 optical in, the 2770 has no usb and dual optical in. And it worked beautifully. At least till I needed something with 2 optical in's. So I bought the new one, brand new. I thought I had the problem solved when I plugged my blu ray player into the hdmi and used the optical out on my tv for sound, then I realized while playing Star Trek(2009), that something didn't quite sound right. Some frontal sounds were just being "repeated" via the rear satalite speakers. I thought it might have just been the cables(fiber-optic) but they're fine. It can't be the receiver itself can it? It can't be. It has one coaxial input and I've been able to get 5.1 surround via my blu ray player in both PCM and bit-stream. I don't know what else to do at this point, sorry for the long post. ANY help would be greatly appreciated. Thank you.

[rbinck]

Many TVs will convert the 5.1 digital audio to 2.0 digital audio for output on inputs other than the internal tuner. That sounds like what is going on. If this is the case, the solution is to connect the devices direct to the surrounf equipment and forget trying to use the TV to switch the audio.

[Doctaspawk]

Originally Posted by rbinck

Many TVs will convert the 5.1 digital audio to 2.0 digital audio for output on inputs other than the internal tuner. That sounds like what is going on. If this is the case, the solution is to connect the devices direct to the surrounf equipment and forget trying to use the TV to switch the audio.

Thank you for the reply, albeit much later than I would expect, though when asking for free advice beggars can't be choosers, or impatient. Anyhow I assumed that might have been the case but still haven't figured out why my xbox, ps3, dvd player, and pc w/dolby digital live extigy all output static/noise when used in digital mode. Before you think about that keep in mind, my sony BluRay player outputs digital just fine, I even play my dvds on it just because of that. And yes I'm using the toslink optical connection not the coax. So why is the bluray player doing what its supposed to do, but not the other devices? Is it a pcm/bitstream thing? Or is it something else entirely? Am I missing anything, need any more info? Any help will be greatly appreciated. Thank you, and thanks again Rbink for responding.

[rbinck]

Yes, It probably is the PCM thing. See if you can set the noisey devices to 2.0 audio to see if it fixes it.

[Doctaspawk]

If I wanted 2.0 I'd use it, but I want 5.1. I'm thinking maybe the Bluray player has its own built-in digital decoder and is sending a pre-decoded digital signal so the receiver doesn't have to do anything but output the sound. Could be I just have a bad decoder in the receiver, idk anymore, but thanks.

Edit: Also, when I play games on my xbox/ps3 and use digital audio via hdmi output, it shows up as Dolby digital on my receivers display when I press the surround button, and it is being output as surround, not fake surround like Dolby ProLogic I/II or HRTF. I can tell when I play games like Mass Effect 1/2, Oblivion, Orange Box(HL2E1/2) and even other types of games, even dvd surround isn't faked. If something sounds like its behind me, it clearly sounds behind me, not reverberation/echoing from the front channels.

[qunidaye]

anything but output the sound