S/PDIF output quality - varies how?

[1UP]

Assuming a transport is emitting bit-perfect output via S/PDIF, does it make sense to still say that one unit's S/PDIF output is "better" than another's?

What (and how do) other requirements exist that determine that S/PDIF quality? Quality of upstream transport / clocks / RCA sockets??

How can digital outputs be different if they are both bit-perfect? Wouldn't this mean the digital content contains something other than bits??

 

[Glassman]

Quote:

Originally Posted by 1UP Wouldn't this mean the digital content contains something other than bits??

spot on, Alec.. in digital sampled systems, there are two information needed to reconstruct the analog signal, one is the amplitude information (the sample value) and then there is timing information.. the first one can be thought of as purely digital information, while the other is purely analog.. so digital part being equal, the is still that analog part, that's never the same.. and both are important..

 

[Rhydon]

In some really high-end audio circles, they say that toslink is an inferior format, and AES/EBU and Coaxial are much more robust and accurate.

-Just a little info

 

[Garbz]

What glassman said is very accurate. In the digital domain, any system can be bit-perfect. Then assuming that every transport should sound the same, and so should every dac based on the same chipset.

But the timedomain is altered and varying, and the ammount it varies from ideal is called jitter. Everything introduces Jitter from the RCAs used to terminate coax S/PDIF connections to the TORX/TOTX terminations on toslink.

The ideal digital cable is perfect 110ohm terminated with XLRs for AES/EBU standards, or 75Ohm Coax cable terminated with 75ohm BNCs for S/PDIF.