Why do digital cables sound different?


I have been talking to a few e-mail buddies and have a question that isn't being satisfactorily answered this far. So...I'm asking the experts on the forum to pitch in. This has probably been asked before but I can't find any references for it. Can someone explain why one DIGITAL cable (coaxial, BNC, etc.) can sound different than another? There are also similar claims for Toslink. In my mind, we're just trying to move bits from one place to another. Doesn't the digital stream get reconstituted and re-clocked on the receiving end anyway? Please enlighten me and maybe send along some URLs for my edification. Thanks, Dan
danielho
I`ve done a test like Osgorth did, and with optical AT&T as a reference.(A-B-C test) First; optical outplayed any "high-end" (high price) coax, actually no match. Even if we could observe some minor differences between the coaxes, they was totally outplayed by the clean open sound from/through the optical cable.
Tryed out some DIY`s too, air-insulated coax and stuff, but none came close to the AT&T digital. Until I made up a coax of my reference IC; the TV-coax Vivanco KX-710. And for some reason this coax just does it all right. Now we were up in the same league as the optical, and after some switching we could observe that the Vivanco-coax was definetly a bit cleaner in both ends, much like the same way it outperforms all other IC`s, then in twin configuration.

Even if I have my thoughts about why they sound different I woun`t try to come up with some answer/guessing. But one thing is clear; there`s a lot more to soundreproduction then what those "theory-heads" comes up with :P
Wire properties can certainly affect digital pulse characteristics. But, up to the point where a data "one" can be misinterpreted as a "zero" pulse characteristics don't affect the information which goes into the D/A converter.
So I don't find it "mysterious" at all that various cables sound the same. The mystery is why some folk think they sound different.
Eldaford - if they affect digital pulse characteristics (different bandwidth) then they produce different amount of jitter. Shielding also affects the jitter since noise causes changes in threshold levels. Some DACs are not sensitive to jitter (like Benchmark DAC1)at all but others are. Impedance matching also plays a part. Many cables ends-up with an RCA connector that is not 75 ohm.
The question is : why people pretend to hear a difference ?

Or why they THINK they heard a difference ?

No need to look further
I don't know if this response has been given before but this is what I know. For digital signal paths the frequencies of concern (pulse rate, pulse edges, etc.) are outside (higher) than the normal audio domain. In fact, they behave more like RF. So, the digital cable is essentially a specialized RF cable. At RF frequencies it is the cable impedance, especially at the interfaces (connectors) that is important because mismatches with the commected components can cause signal reflecttions. What this means, obviously, is that phantom bits may been ADDED to the digital stream. So, a good quality digital cable is just as important, if not more so, than your analog interconnects!