Why do digital cables sound different?

I think I am repeating myself, but continue to get replies which imply that the only reason why digital cables could sound different is bit errors. This is not the reason at all - the reason is jitter - noise-based and time-based distortion. The problem is not about distortion causing a DAC to read a 0 as a 1, or a 1 as a 0. It is about the fact that we are talking about real-time transmission and that a DAC produces harmonic distortion at its output when the arrival times of the 0s and the 1s are not perfectly, regularly spaced. I really am having trouble saying this in as many different ways as I can. It is not about redundancy so that when an error occurs the data can be resent - we are not talking about data packet transmission here. Bandwidth capability is in fact an issue here. Even though the bandwidth for data transmission is low by most standards, if the cable was only just able to transfer the data accurately then the square waves would be very rounded indeed and jitter errors at the DAC would be enormous. Higher bandwidth cables allow sharper corners to the square wave with less undershoot or overshoot. Optical cables are also free from earth noise adding to the signal. It is not about bit errors, it is about timing based distortions. I work with loads of PhD telecommunications engineers but their grasp of these concepts is slight at best, because it is irrelevant for the audio fidelity needs of telephony and irrelevant for data packet transmission. But the best of them acknowledge that their training is insufficient for high quality audio.

Redkiwi: I get it. It is not only that you say yes and no, but "how" you say it as well. As far as I know nothing is perfect and there are always variences to be had. The sub atomic clock in Denver is pretty accurate, but I would assume that DAC's and digital transmission lines are not even in the same ballpark. Perhaps when we get organic based DAC's all cables will sound the same?

Ehider, I am still the skeptic, but I appreciate your viewpoint and candor. BTW, Is your employer Burr Brown? Thanks for the reply.

I am not sure we are disagreeing - over and undershoot being a capacitance issue, is the same thing as saying it is a bandwidth issue (but not necessarily the reverse). So far as I know there is no capacitance issue wrt glass cables, but they sound different from one another.