Originally Posted by maccam94
I'm running Gentoo and Ubuntu on a eVGA 680i motherboard, and I can't get clear digital output over the digital optical (toslink) output in either distro.
00:0f.1 Audio device: nVidia Corporation MCP55 High Definition Audio (rev a2)
Subsystem: nVidia Corporation Unknown device c55e
Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
Status: Cap+ 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR-
Latency: 0 (500ns min, 1250ns max)
Interrupt: pin B routed to IRQ 21
Region 0: Memory at cfff0000 (32-bit, non-prefetchable) [size=16K]
Capabilities:  Power Management version 2
Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot+,D3cold+)
Status: D0 PME-Enable- DSel=0 DScale=0 PME-
Capabilities:  Message Signalled Interrupts: Mask+ 64bit+ Queue=0/0 Enable-
Address: 0000000000000000 Data: 0000
Masking: 00000000 Pending: 00000000
Capabilities: [6c] HyperTransport: MSI Mapping
I've loaded the snd_hda_intel module with the model=6stack-digout, and while I can get analog audio output (which my reciever converts to surround with Pro Logic) I can't get true 5.1/DTS output. I've managed to force audio out the card using the digital pcm (alsa thinks it is at hw:0,1 apparently) but when playing DTS tracks all I get is silence and a stereo dts signal appears on my reciever, or when playing regular audio through it it sounds almost like the volume is too high (sounds really cruddy) even though it's quiet. Whew there are probably a lot of run-ons up there, but I dunno how to explain it better.
Basically I get audio, just not full quality, and when I try to tweak it so that it works, the sound quality is terrible. I'd really like Quake 4 and Counter-Strike Source (using cedega) and DVDs to utilize my true 5.1 surround sound setup. Help from anyone who has this working or has ideas would be MUCH appreciated. Thanks!
I know this is kind of a negative answer, but onboard audio has always had problems. The other thing is, if the Digital PCM were to work perfectly, then that would more than make up for lack of positional audio, b/c positional audio thru dts 5.1 is compressed and stereo isn't. You can't do any better than digital stereo, IMO.