As I state earlier, wrt to the RCA cables, we didn't do any A/B blind testing. Too hard. I could not hear a different on my system. My friend did on his. I take with a grain of salt and just like how the RCA cables I built look. I make no other claims.
WRT to the Utopia, there is no way one person can do bling testing. I certainly did A/B testing, and it was clear that even though I wanted the silver cables to sound better with the Utopia, there was a clear difference in sound. It truly sounded awful compared to the copper cables I built, as well as the stick cable. That is why I reterminated it. I don't have the right measuring equipment to measure the not so subtle differences, and I already changed the cable. As for it sounding better on the PMx2, I would say it sounds the same as the stock cable, and it's possible the copper cables I'm made with Mogami wire sound a little mushy or warm. No scientific way to prove that with only one person. A/B testing of cable is hard enough. Blind testing is even harder. Note that I generally cannot hear a difference between cables. I'm compared my DIY cables to the best from other vendors, and to stock, and generally I cannot hear a difference.
Is inductance and capacitance directly proportional to wire gauge? Would the materials used int he wire also affect these values? Would the dielectric and possible the insolation?
No, resistance is varies in proportion to wire gauge. Inductance increases as conductors (or groups of conductors) are separated (insulation dielectric has no effect on inductance), capacitance decrease as conductors are separated, increases as they are brought closer to each other, and insulation dielectric properties have an effect. But the resulting impedance changes caused by capacitance and inductance are combined with wire resistance, and only cause an audible effect when the result creates a frequency variable attenuator when terminated with a low impedance load. And never happens with audio interconnects, very rarely in speaker wires. There have been wires with deliberately high inductance (those wires where two conductors are separated about a foot apart), and high capacitance, and yes these can be audible. But you could do the same thing with a capacitor or fixed inductor...or better yet, with a DSP, as it's just a simple filter.
But the multiple wire gauge "theory" isn't about any of that, it's referencing a real property of AC signal propagation over conductors called "skin effect", where progressively higher frequencies travel more on towards the surface of the conductor, less toward the middle. The property is real, calculable, and measurable, but also a complete non-issue in audio, unless you're dealing with very long cables carrying high currents, like speakers. And, oddly, larger gauge wires exhibit skin effects more readily than smaller ones, because smaller wire has higher resistance which swamps all skin effects, and it because of its smaller size has less differential between skin conductivity and conductor body conductivity.
The short story is, there is absolutely no advantage to multiple conductor size wire cores in RCA interconnects because the wire gauges involved are all too tiny to have any differential skin effect at audio frequencies, and...and this is key...the load at the receiving end is far too light for any of this to create a frequency dependent voltage divider.
You can run into skin effect issues with large wire gauge, and very long runs at speaker level. But note that for skin effect to be a problem at audio frequencies it must present enough impedance change that the result becomes an audible difference caused by the impedance and the load. So sure, 20kHz through a 10ga wire uses only 68% of the total conductor cross section, where 20Hz uses 100%, but the resistance of 10ga wire is already so low that a 32% change at 20kHz is meaningless. Multiple conductor sizes makes no sense for power cable other than to provide a degree of flexibility. But general stranded wire does that even better (and cheaper).
Oh, BTW,
these guys explain it better than I. Note that 22ga wire at 20kHz uses 100% of the conductor. A more complete chart of the properties of wire sizes is found
here.
One more note about comparing wires. Sorry, ABX testing is absolutely necessary, and yes, it's difficult (read: expensive). One person can do it, though. You need an ABX comparator, a switching device that permits the swapping of devices (including wires), and presents the tester with an A, B, and X choice where X is either A or B, but randomized, and not known until testing is complete and results are compiled. These things are available, and cost somewhat less than the most expensive wire in the world. Mine was made in the early 1980s, no longer available, but it has been used to test wire. Except for the deliberate high L and C junk, there is no audible difference between wires of the same gauge used for speakers, and no difference in interconnects (again, excluding the deliberately goofy ones, badly made, or excessively lone ones). The effects of wire on audio have been studied to death, yet the lunatic fringe still remains and offers weird wire for sale.
I made some solid core silver cables for various headphones, and there where differences. In one case, the Utopia, the cable make it sound horrible. I reterminated the cable for the PMx2, and I really liked the sound from the PMx2 with the silver cable. I made a hybrid copper/silver cable cable for the Utiopa, and I like it.
