Audio debate- HDMI vs S/PDIF

[Tom Moreno]

Alright, assuming we exclude the obvious caveats of multi-channel PCM and lossless surround format transmission, I've heard a few times that using a coaxial digital connection as opposed to HDMI for stereo PCM transmission results in better quality. Is this an absolute? Can anyone offer any explanations as to why this might be? Thanks

 

[kinda]

I can't really at a technical level just that I've seen it stated a lot that HDMI is very prone to jitter. I'm not sure why it should suffer from it more than other transmission methods.

 

[Anonymous]

Another magazine offered up this month that co-axial S/PDIF & HDMI are mechanically the same in that you can buy different cables which may effect the sound in some minor way (and I know I'm on dodgy ground here given its a digital signal) and thus allow (I'm going to be careful with this next word) "tuning" by the user, but that Optical S/PDIF (subject to decent electrical to optical convertors already in the components) will leave the signal untouched (certainly over short distances)

Not exactly the answer to your question but I'd offer up that given the number of conductors in HDMI there's a slightly higher chance of cross talk in very long runs or in badly shielded cables - that cross-talk could be misinterpreted (or even simplified by authors of the statement) as "jitter"

 

[Anonymous]

From what i understand the HDMI will handle a greater level of information transfer but the optical is a bit more accurate in it's timing ie. less digital jitter.

Perhaps why I haven't seen a DAC with HDMI input?

 

[Anonymous]

If you exclude all the mumbo-jumbo that tends to occur in hi-fi discussions, it comes down to this:

The sound quality of a digital source is dependent on two things:

The source file and the D/A convertion (or rather the analog side of the DAC).

All DACs have some sort of system (buffering, re-clocking) that makes jitter a non-issue in real life. Jitter will never cause anything close to audible effects.

No stereo DACs that I know of has HDMI inputs. Thus HDMI will always use the built-in DAC of a receiver, even when used for stereo sound.

Some people will prefer the (possibly slightly 'coloured') sound of an external DAC to that of an internal one.

 

[Andrew Everard]

Thanks for introducing some mumbo-jumbo of your own, Fahnsen...