I have been trying my hardest to get my audiophile surround files playing through to my new receiver. I have an HDMI cable coming from my ATI HD4870 graphics card, which supports up to 8 channel 24 bit 192kHz. I have been able to play DTS/DD DVD formats via Windows Media Player and DTS wav files via foobar2000 when I set for WASAPI and 16 bit (both work in multi-channel).
I want to especially play my MLP DVD-Audio files of 24bit 92kHz 5.1 sound, but so far have only achieved stereo via Winamp, VLC player, foobar2000, or WMP. When I try in foobar2k it says "stereo downmix", and when I check the settings for my HDMI in winamp->options->preferences->output->directsound output->speaker setup: stereo (unchangable). I would also like to play some of these that I have dl'ed as FLACs (I don't like converting audio due to inevitable loss of data on some level), and so far have not been able to play multi-channel in Winamp, WMP, VLC, foobar2000, XBMC - only outputs as stereo to my amp. I also have some AVCHD discs in multi-channel that I can play via TotalMedia Theatre 3 and get there quite well.
I have had great success with playing these through my analog 3.5mm jacks to my quad+sub sound system on my PC. I think the greatest setback is that I haven't figured out how to get my system giving multi-channel LPCM to my receiver - the only formats that have been getting there in multi-channel are either DTS or DD. If I hadn't already scoured the internet, I wouldn't be here. Thanks