Why do digital coax cables matter?

Huge thanks for that eloquent explanation Steve. I was hoping you would see this thread. It's making much more sense to me now. One of the best threads on these Audiogon forums I have read in fact. Thanks again.

"Some manufacturers like Sonic Frontiers implemented an I2Se interface to avoid these issues."

I2S is available on Empirical Audio, PSAudio, Wired for Sound and other gear. Some SE and some differential.

Even I2S requires a good cable. Actually more-so than S/PDIF because the frequencies are a lot higher on I2S.

"I guess my message is, if you supposedly need a $500+ coax cable to get the job done then maybe you need to choose a better interface. Stack the deck in your favor at least, don't be a victim!"

Like what interface? They all need good cables.

Steve N.
Empirical Audio

...True, but we are not talking about bit errors here, we are talking about psecs of jitter. The cable matters, as does practically everything else...

Jitter is directly tied to the Eye pattern tests, so the concept is valid for digital audio. The percent jitter is actually calculated off the eye pattern. The jitter in turn can be used to predict BER rate.

Rower30: what you have outlined is my understanding as well, based on Rf transmission theory. Impedance match at the connectors and loss tangent (dissipation factor) in the cable are the two key parameters.....everything else is secondary. That is why cheap CAT5 cable is far superior to most analog audio cable for digital transmission.

Also reclocking the data at the DAC is the key to superior reproduction.
Putting the clock in the data stream was poor engineering from the start. Fortunately, HDMI 1.3+ provides for this and is generally superior to any SPDIF interface, (even with million dollar cables), for this reason. Buy an Oppo BDP-95 and a DAC with an HDMI 1.3 input (Meridian HD621), and you won't have to worry about jitter.

Steve Nugent Wrote:

'Jitter measurements are a rat-hole IMO. Jitter has never been effectively correlated with SQ anyway, and based on my experience, it is very dependent on the spectral signature of the jitter. Single jitter measurements are useless to say the least.'

Bingo - we have a winner.

I have mucked around with all sorts of sources and thats it exactly.

Thanks
Bill