Why do digital coax cables matter?

Surprised nobody has mentioned the SPDIF clock which is an analog RF waveform (if I'm not mistaken) that must stay in sync with the data.

Not sure if AES/EBU any better in that regard, but it is supposed to be easier to guarantee impedance match (110 ohm in this case).

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

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!

"Perhaps you didn't test the right cables, or your preamp creates enough distortion, noise and compression that you dont hear the benefits because they are masked. This is fairly common when using an active preamp. I dont use a preamp, so I dont experience this masking anymore. It's a system after all, so every component and cable matters."

Maybe. But I do hear differences in most everything else I tweak beside digital source and ICs. So I think I have the relative magnitude right at a minimum. I hear a lot of systems and live music and I do not hear any distortion or dynamics issues of significance, but of course we know such things are always in play to some extent in home audio.

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.