Why do digital cables sound different?

Actually, if a digital waveform is distorted to the human eye on a scope, then it is distorted. There are built in test parameters you can put in to determine if the waveform is in spec or out of spec over a period of time.

Check out this link:
http://www.scientificarts.com/logo/logos.html

You don't need to know the math to see what they are talking about. There are some eye diagrams there which are very "open" and hence have excellent data transmission with no errors and there are some which are "closed" which are filled with errors.

Just 'cause its digital doesn't mean it isn't lossy.

Spatialking...A digital waveform does not represent the information being communicated (a "one" or a "zero"). The waveform is sampled at some specific instant of time to determine if it is above or below some threshold. Where the signal goes in between sample times is completely irrelevant. All that matters is that the sample time be chosen so that it is well away from leading and trailing edges of the waveform where the signal level is changing rapidly and might be misread.

In a complex digital system that I worked on (Missile guidance) we had dozens of analog signals being sampled and digitized, and many digital signals being used to generate pulses of power (amperes) to control things like gimbals. All in the space of a 9 inch sphere, so you can imagine the electrical noise environment! By very careful selection of sampling times and signal sequences it all worked fine, although you would never have thought it possible if you looked at the raw analog signals. The bottom line is that a sampled data system does not exist except at the sample times.

Missile guidance systems? OK, from now on I will definitely be nicer to Eldartford.

Okay, now what can I expect to hear when I use a Balanced AES/EBU cable rated at 110 ohm (in place of a digital coax at 75 ohm)?

And will the highly contested and aformentioned replies to Dan's original post apply?

--ksr

Jitter