"Although BNC would theoretically be preferable to RCA connection, there is actually next to no audible difference between an spdif using either. Steve mentions that the BNC must be designed for a particular cable, which frankly is a dubious statement. The connectors 'are what they are', and the cable that exists to connect them together should offer as close to the 75ohm Zo as is possible, which is not difficult."
Whether you hear differences will depend on your source and your system. If the source is truly low-jitter and has fast risetimes to insure that the low-jitter is maintained through the receiver, the BNC will make a BIG difference.
Termination of the coax to the RIGHT BNC connector is critical. Even a millimeter difference in diameter inside the connector will change the impedance. Many so-called 75 ohm connectors are also not 75 ohms exactly.
"If using RCA connectors, the shorter the better, i.e. Furutech FP126, and designing the cable to terminate at 75ohms exactly can make a perfect match. Using adaptors also makes little difference, both on a scope and audibly. Saying that, I do agree that more equipment manufacturers could do with offering them.
Cable length should not be an issue if the said cable is an exact impedance match for the output and input, as refections should not occur."
Also untrue. There will ALWAYS be reflections, even in the best of cables and connectors. The reason to have a 1.5m minimum length as recommended in my paper is to insure that when those reflections get back to the receiver, that it is not when the receiver is detecting the edge. Its just common-sense.
You obviously did not read my white-paper, which has been the standard for S/DIF cable length for many years now.
Steve N.
Empirical Audio
Whether you hear differences will depend on your source and your system. If the source is truly low-jitter and has fast risetimes to insure that the low-jitter is maintained through the receiver, the BNC will make a BIG difference.
Termination of the coax to the RIGHT BNC connector is critical. Even a millimeter difference in diameter inside the connector will change the impedance. Many so-called 75 ohm connectors are also not 75 ohms exactly.
"If using RCA connectors, the shorter the better, i.e. Furutech FP126, and designing the cable to terminate at 75ohms exactly can make a perfect match. Using adaptors also makes little difference, both on a scope and audibly. Saying that, I do agree that more equipment manufacturers could do with offering them.
Cable length should not be an issue if the said cable is an exact impedance match for the output and input, as refections should not occur."
Also untrue. There will ALWAYS be reflections, even in the best of cables and connectors. The reason to have a 1.5m minimum length as recommended in my paper is to insure that when those reflections get back to the receiver, that it is not when the receiver is detecting the edge. Its just common-sense.
You obviously did not read my white-paper, which has been the standard for S/DIF cable length for many years now.
Steve N.
Empirical Audio