Why do digital cables sound different?

Another point: it could be that different cables have differing degrees of shielding effectiveness, and therefore, generate different levels of RFI which is coupled back into the analog electronics. P.S. Don't knock science and engineering. That's what gave you something to listen to. Empiricism has its place, but progress depends on interpreting those results in the framework of physical laws and analytical principles -- or else we'd still be riding ox carts with wooden disc wheels over stone bridges.

1439, I agree with you as well, but I think there are enough possible explanations available to accept that there are differences between cables, and get on with picking the best one for their system, instead of continuing to deny that reality.

I'm not denying reality, just looking for plausible explanations of it, and pointing out that existence of a plausible explanation (other than placebo effect) means that our beloved audio equipment has design deficiencies. Consider the case of digital cable interconnects between computer equipment: either they work right or they don't. One does not swap printer cables, for example, hoping to increase the resolution of the printed page! If it is indeed the case that digital cables have effect on the sound, why is this an acceptable situation? The whole point of digital technology is to avoid these degradations entirely. I expect more for my dollars, and want to spend more on source material, and less on "work-arounds" (e.g., esoteric cables needed to compensate for performance shortfalls in the equipment design).

1439, I was speaking generally and not personally. It seems to me that some high end companies like VAC and Mark Levinson are adressing a similar issue by manufacturing integrated amps, (no need for pre-amp to amp interconnects) I am sure that one day cables will be eliminated altogether. 1439, I'm with you on wanting to spend more on source gear, but even with well designed equipment the cabling still effects sound. To get the best almost always takes more money. .

1439 - I agree with your point 100% and have made it myself many times - if differences are heard using different cables, the bits must be being altered (a bad thing)and if they are, then we as consumers should be demanding a better technology for the interface, not spending a bunch of money on cables and transports. As you say, you can transfer bits perfectly in the computing world with good quality but relatively cheap cabling and absurdly inexpensive hardware. If a DAC with an ethernet input interface was available, it would be easy to set up a whole-house music distribution system that performs as well (or better, if transport technology is as spotty as it would appear it is) as the best transports. Hopefully such an interface isn't too far off in the future.