But there is the attitude mostly in this thread to just dismiss it as "we all know it's nonsense so why bother?" whereas it would seem more fruitful perhaps to actually address the claims.
I think JA's claims have some degree of plausibility to them. I am not dismissing them as nonsense, I am saying they are serving as justification for other nonsense, such as the subjective review you linked to.
I would be interested in seeing any measurements that he may have that support his conjectures. I have seen some measurements on cables that indicate differences large enough so they could potentially be audible - however, the quality of the data was poor and there was inadequate description of test methods and conditions, as well as basic information such as length of cables, for the data to be usable. I have also seen descriptions of blind listening tests where audible differences were identified, again with inadequate supporting information.
JA is equipped to provide much higher quality data, if he chose to do so. But he hasn't. In the absence of evidence, the null hypothesis prevails.
But perhaps an opportunity is missed in going through his 6 points and quickly mentioning why they are unlikely to account for audible differences in cables?
If we want to match conjecture with counter-conjecture, here's a quick effort:
1) Optimum conductor diameter: Possibly true mathematically, most likely insignificant practically.
2) Dielectric nonlinearity. It's a real effect. It can matter in capacitors. Does it ever matter in cables? Unlikely, because the capacitive current is a small shunt current on a low impedance source. An IM distortion measurement would tell. JA has an audio analyzer and could do that measurement.
3) Mechanical structure of conductor. Microstructure does alter resistance. But so do many other things. In the end it's just resistance, regardless of the cause.
4) Grounding problems, loading of unterminated cable effect on negative feedback. Grounding problems are real, not sure what his point is. Signals propagate in an unterminated cable through a series of reflections, stair stepping their way to the final value. That would matter in an microwave amplifier. But audio frequencies are so low and the cable distances so short, it is completely invisible. The cable looks like a lumped capacitance and resistance, with no special effect on a feedback amplifier.
5) RF shielding. Yes, RF shielding can matter, and it can be measured. There are many standard test methods for RFI.
6) Microphonics. Yes, it exists, and it can be measured.
So we have a number of conjectures with a physical basis that are measurable. I eagerly await the data from those who claim these effects are audible.