Difference between onboard S/PDIF Optical Toslink output vs Video card HDMI

[Stealth3si]

In terms of sound quality and number of discrete audio channels (stereo vs 5.1), is there a noticeable difference between my computer's onboard soundcard's S/PDIF Optical Toslink output versus MSI Radeon Asus 7850 HDMI sound output?

Originally, I wanted to hear my PC games via my computer's discrete Asus DX sound card's S/PDIF Optical Toslink output to my Denon 1712's S/PDIF Optical Toslink input but the Asus's S/PDIF Optical Toslink output didn't work (it broke), so I'm currently hearing my PC games via my video card's HDMI output.

If I wanted to hear my PC games via my computer onboard Realtek sound card's S/PDIF Optical Toslink output, I must buy an optical cable to connect to my Denon 1712 receiver but before I could waste money I was wondering if anyone knows from experience if I would get the same high quality digital 5.1 sound coming from MSI Radeon Asus 7850 HDMI sound output?

[jman98]

There really shouldn't be any difference now. However, some audiophiles argue that the nature of Toslink can introduce jitter. I would say that this is an argument for the people who also still believe that vinyl records are the greatest sound reproduction technology ever invented more than having any practical value. I strongly doubt you would be able to tell any difference between HDMI and Toslink.

Amazon and Newegg.com are both great sources for cheap cables of all types and unless you just have to have it immediately, their prices are so good that even with shipping the cables you can buy through them will still be cheaper than what physical stores will charge, sometimes 50% or even two-thirds cheaper.

[Stealth3si]

Thanks!

Now I'm wondering which one to use.

Which of these two would you use and why?

[yoda313]

I'd like to chime in on this a bit.

This is for gaming right? I don't have a powerful enough computer to do modern games so I'm not sure about this - do they have DOLBY TRUE HD these days for games?

If so you won't get the full hd over fiber optic.

You'll still get the core 5.1 out of it like a bluray movie would do. But for the full res audio you'd need to do hdmi.

So there would be a difference between fiber optic and hdmi if hd audio is involved.

However like I said I don't know if hd audio is in modern pc games yet. I do console gaming so I don't know what they pack into the newest pc games as far as audio goes.

[jman98]

I think yoda313 is correct. Note that I am not a gamer so I have no idea what audio formats games use. I was honestly thinking along the lines of AC3 and DTS rather than current lossless high def audio formats.

[yoda313]

I think yoda313 is correct. Note that I am not a gamer so I have no idea what audio formats games use. I was honestly thinking along the lines of AC3 and DTS rather than current lossless high def audio formats.

Not a problem.

Actually I didn't even mention dts master audio nor lpcm lossless.

I know at least on ps3 games dts master audio is more common that it is not. I don't think dts master audio is on xbox 360 games but they do have digital audio of course.

[sanlyn]

I would say that this is an argument for the people who also still believe that vinyl records are the greatest sound reproduction technology ever invented more than having any practical value.

They still believe it. It's still true. Vinyl and upscale analog gear are enjoying new popularity.

I strongly doubt you would be able to tell any difference between HDMI and Toslink.

Depends on the cable. In this case, I doubt it as well. PC "hi-fi" is clearly for those who can't tell. Spending good $$$ for it is a waste, too. Practically any cable or hookup will do.

[turk690]

You'll still get the core 5.1 out of it like a bluray movie would do. But for the full res audio you'd need to do hdmi.

Blu-ray movies that have DTS-HD Master audio can and do output a lossy 'core' DTS stream from that. In other words, the normal DTS stream, as output from the SPDIF connector, is a subset of the existing full lossless DTS-HD Master audio stream that gets output through HDMI.
On the other hand, a Dolby AC3 stream (like those on most movie DVDs) is NOT a subset of & cannot be extracted from a Dolby TrueHD stream. The two are separate & incompatible, which is why blu-ray movie discs that ONLY have a Dolby TruHD track will not have any output over SPDIF. As insurance, blu-ray specs have mandated that if a publisher wants to use Dolby TrueHD on a movie blu-ray, a separate Dolby AC3 track should also be present so that something will be output from the SPDIF connector. This somewhat akward arrangement is probably the reason why the vast majority of blu-ray movie discs have DTS-Master audio instead of Dolby (at least for the main audio track).
The arrangement with games may be similar but I wouldn't know. Just note the above.

[pandy]

In terms of sound quality and number of discrete audio channels (stereo vs 5.1), is there a noticeable difference between my computer's onboard soundcard's S/PDIF Optical Toslink output versus MSI Radeon Asus 7850 HDMI sound output?

HDMI is superior interface in terms of quality and capabilities to S/PDIF. However in typical listening conditions you should not hear any difference between HDMI and S/PDIF.
Additionally HDMI source can in theory compensate in automatic way lipsync.

[yoda313]

You'll still get the core 5.1 out of it like a bluray movie would do. But for the full res audio you'd need to do hdmi.

Blu-ray movies that have DTS-HD Master audio can and do output a lossy 'core' DTS stream from that. In other words, the normal DTS stream, as output from the SPDIF connector, is a subset of the existing full lossless DTS-HD Master audio stream that gets output through HDMI.
On the other hand, a Dolby AC3 stream (like those on most movie DVDs) is NOT a subset of & cannot be extracted from a Dolby TrueHD stream. The two are separate & incompatible, which is why blu-ray movie discs that ONLY have a Dolby TruHD track will not have any output over SPDIF. As insurance, blu-ray specs have mandated that if a publisher wants to use Dolby TrueHD on a movie blu-ray, a separate Dolby AC3 track should also be present so that something will be output from the SPDIF connector. This somewhat akward arrangement is probably the reason why the vast majority of blu-ray movie discs have DTS-Master audio instead of Dolby (at least for the main audio track).
The arrangement with games may be similar but I wouldn't know. Just note the above.

I have a ps3 and a sd digital amp that does dd and dts. I have it connected via fiber optic.

I can play 5.1 from a dolby true hd 7.1 track. I just visibly confirmed it with my Star Trek 6 bluray. Its only english audio track is dolby true hd 7.1 (correction - its only non-commentary digital surround sound track is dolby true hd - there are commentary tracks of course). I get normal dolby 5.1 from it just fine.

Now technically it might be the ps3 doing something to output the 5.1 from the dolby track. I don't know for sure. However the movie only has a true hd track.

I believe the same is true for the Transformer movies and the Dark Knight movies. Many don't have dts audio but I get normal 5.1 ac3 out of it just fine.

Sorry for going a bit off topic here.

And I don't know if that is the player doing it since you are claiming there isn't a core in the dolby true hd. However it works I get a 5.1 sd from the true hd 7.1 track somehow. It certainly isn't my amp as it was before bluray.

So your statement might be technically correct and I am misreading it in that the player is doing some trickery to get a naked ac3 5.1 track. Regardless I can do ac3 5.1 from just a 7.1 true hd track. (there is a 5.1 track on the Star Trek 6 disc but its french and I was listening to the english track).

[turk690]

... I get normal dolby 5.1 from it just fine.

Now technically it might be the ps3 doing something to output the 5.1 from the dolby track. I don't know for sure. However the movie only has a true hd track.

I believe the same is true for the Transformer movies and the Dark Knight movies. Many don't have dts audio but I get normal 5.1 ac3 out of it just fine.

I have also encountered this, but on examination, a 5.1ch AC3 version of the main Dolby TruHD track is also available. It may be standalone with its own address, or interleaved with the TrueHD stream so all you see is that one track. (This is two distinct tracks in one, not a genuine single track like DTS-HD which consists of its 'core' and 'lossy' parts.) Often it's not presented or selectable in the audio menu, unless it's a different language or commentary track. But the qualifier here is, it's easy to tell because all audio will only come from HDMI, (or from analogue outputs in case you have one of those expensive blu-ray players with built in HD audio decoders from Panasonic and Denon) and none from SPDIF, unless, as you say, separate processing (internal re-encoding to AC3) is happening just so for something to appear at the SPDIF connector, or it's the first case.
Re-encoding is not new: an option in upscale DVD players when the format was new re-encoded the 5.1 AC3 track to 2-ch LPCM with the existing channels mixed for Dolby Surround so that they can properly be decoded with existing analogue-domain Dolby Surround decoders.

[yoda313]

and none from SPDIF, unless, as you say, separate processing (internal re-encoding to AC3) is happening just so for something to appear at the SPDIF connector.

That must be what is going on. The ps3 doesn't have multichannel out - my amp has multichannel in though. But I am connected via spdif.

FYI my sd digital amp is a sony model that I bought just before THE PHANTOM MENACE came out on DVD. I wanted in on digital surround sound. So whenever Episode 1 came out (on dvd that is) that was right about the time I bought my amp. Well before bluray and hdmi.