mellows said:
"In the cable" the impedance is low. Ie, one end of the conductor (the driven end) is at a low impedance, so the voltage on the whole conductor is controlled by the driver chip, much more than by the interfering signals. If both ends of the cable were connected to a high impedance, the interference could come booming on in unimpeded, unless there is a (low impedance) shield to keep the interference off the signal conductor.
Ahem! Careful now. There's a lot of folks here that may jump on a juicy argument like that.
One can say, and with proper empirical backup, which I can't afford to gather (nor have the brains to gather really) that an SPDIF link can have a really significant effect on the audio that you generate from it. There's a clock signal embedded in there by which the whole Nyquist theorem stands or falls (I exaggerate only a little by phrasing it that way.) To the extent that the cable introduces skew in the signals rise/fall-time, it may well have an effect, as it may introduce clock jitter to the order of some 200ps. For the newer 192kHz/24bit format, this timing/jitter issue becomes a whole lot more important again. I'm not even sure what tiny amount of jitter is allowed there to satisfy the theory. I try not to think about it and started buying vinyl again when I learned that the PCM coding is also very related to the analog signal. It is not just random noise when you compare the two. So grounding becomes that bit more interesting. Often enough, the SPDIF cable does that grounding. There may be a handful of clocks on either side of that cable going dilly at 10s of MHz. Fun stuff, given the dynamic range required of the system.
Now seeing as there are people here that understand all of this much better than I do, like our friendly moderator here, I'm hoping they don't see this. Then they won't jump in and tell me not to talk half-baked nonsense off topic and off on the side here, deceiving the youth. Have you counted the subjunctives in the paragraph above?
If you want to start a fight, start a cable thread in the General Discussion forum. There are too many angles, inviting too many low blows. There will be nothing mellow about it. Promise.
I'll just add my own take on analog cables here. I won't participate in the fight. Yes they sound different to me. But I always want to know why. I've seen no explanation that didn't come down to "Ours is the best, just trust us." I don't trust easily. Especially not when I'm being ripped off. R50/m is inexcusable for Copper/Silver/Teflon. And that would be dirt cheap interconnect in the Home Audio hoax. The whole business is on a par with the Broadcast Quality hoax, and the Pro Audio hoax. But they do sound different. Which is why I suggested lamp cord and dead phone charger cable. You never know...
