Jinjuku, to clarify a key point in several of my previous posts, the "RF noise" I have been referring to, that might bypass the ethernet interface and buffer memory in the receiving device and affect the timing of D/A conversion and might also affect analog circuitry further downstream, is NOT primarily noise that is picked up by the cable due to antenna effects. And for that matter it is NOT primarily noise that might be present in the cable due to ground loop effects.
As I said in one of my posts dated 4-25-2018:
And the amplitude and spectral characteristics of that noise/crosstalk/coupling can be expected to vary as a function of various characteristics of the cable. Such as its bandwidth, which in turn directly affects signal risetimes and falltimes, its impedance, which in turn directly affects signal reflections and hence waveform distortion and hence the spectral composition of the signal, its capacitance, the twisting of its conductors, and its other physical characteristics.
And as I also said earlier:
Regards,
-- Al
As I said in one of my posts dated 4-25-2018:
In addition to the effects of shielding on radiated emissions, shielding would presumably also affect the bandwidth, capacitance, and other characteristics of the cable, in turn affecting signal risetimes and falltimes (the amount of time it takes for the signals in the cable to transition between their two voltage states), in turn affecting the spectral composition of RF noise that may find its way past the ethernet interface in the receiving device. Also, small differences in waveform distortion that may occur on the rising and falling edges of the signals, as a result of less than perfect impedance matches, will affect the spectral composition of that noise while not affecting communication of the data.In other words, the RF noise I have been referring to, that might bypass the ethernet interface and buffer memory in the receiving device and affect downstream circuitry, results primarily from the energy of the SIGNAL ITSELF! Perhaps "crosstalk" or "coupling" of some of the signal energy would have been better ways to refer to it.
And the amplitude and spectral characteristics of that noise/crosstalk/coupling can be expected to vary as a function of various characteristics of the cable. Such as its bandwidth, which in turn directly affects signal risetimes and falltimes, its impedance, which in turn directly affects signal reflections and hence waveform distortion and hence the spectral composition of the signal, its capacitance, the twisting of its conductors, and its other physical characteristics.
And as I also said earlier:
Putting it all very basically, responses by those claiming ethernet cables won’t make a difference nearly always focus just on the intended/nominal signal path. The basic point to my earlier posts is that in real world circuitry parasitic/unintended signal paths also exist (via grounds, power supplies, parasitic capacitances, the air, etc.), which may allow RF noise to bypass the intended signal path to some extent, and therefore may account for some or many of the reported differences.Real world circuits do not necessarily perform in the kind of idealized manner that is almost invariably assumed by those who assert that ethernet cables cannot make a difference. And while I am certainly one who recognizes that in general anecdotal evidence should be taken with multiple grains of salt, IMO there is a more than sufficient body of anecdotal evidence, provided by audiophiles whom I consider to be highly credible, to conclude that ethernet interface circuits commonly deviate from that idealized model to an audibly significant degree.
Regards,
-- Al