jea483,144 posts10-22-2019 9:40am"And where did I say in any of my responses to you anything to the contrary?"
- mainly your statements were gobbly gook, so I just did my best with what I was working with.
"And that relates to wire directionality how? Are you saying because of your statement, flipping an analog or digital coax cable end for end can’t possibly make a difference?"
"Again the shield of a coax is also the signal ground and is connected at both ends. Your above statement does not apply then does it?"
- Again, the outer conductor is not really a shield, not in the traditional sense. It does not "shield" the inner wire as most think, but the overall construction does reject noise, similar to how a twisted pair is not shielded but has inherent noise rejection due to the construction.
- Outside of a single ended shield connection, I am saying we are talking audio frequencies for analog signals, and either low frequencies, short lengths versus frequencies/edge speeds, and/or effectively time-non-dependent digital signals, such that a simple bulk-model, independent of direction is going to more than suffice. Even coax for 100GHz signals, where timing is truly critical, is bidirectional, because the impedance is controlled along the length. Transmission line effects don't come into play at audio frequencies. Skin effect (inaudible anyway), works the same in both directions. Short of intentionally adding unidirectional circuitry to the cable, direction is not going to matter for analog. For digital, at least w.r.t. audio, slow edge speeds coupled with tolerable matching are such that any induced jitter is near nill, and coupled with the variation in the two directions is effectively 0, and in any competent DAC is going to suppress jitter by 10's of db in addition, if not buffered such that any jitter on the incoming signal has no impact on the output.