I can only speak from experience with the Torii on cable quality and size, as I did not do enough articulate exploring with power cables before the Tori. I definitely noticed different cables sounded different before, but now I hear what causes the differences since I have been experimenting with a lot of different cables, materials, ends, sizes.... both for the Torii, and the rest of my components.
When I needed a cable to pull more spaciousness and micro detail from my new PSAudio P5, none of the many very good cables I had quite did it for me. A PSAudio AC12 was the best, but not good enough with the P5, at least not enough to make the combination transparent enough for me. So I decided to make a cable that conceptually could open the P5 to the level of open transparency I needed.
The original 11 gauge cable was too lean whether in the P5 or Torii or DAC, but it was of multi-gauge silver plated copper with Rhodium ends, the combination intentionally making a fast and very revealing cable...not warm, warm being one the problems I had with the P5 signature.
Building it up to 8 gauge, the very same cable and materials, it became notably deeper, warmer, more punchy, now giving very good balance and openness from the P5... deeper, but tight bass, more warmth, and powerful speed without sacrifice to now very good spaciousness, micro detail, and flawless integration of frequency regions.
It may be Rob's 7 gauge TWL cable acts thick and sluggish at Pal's due to the Torii's crazy ability to put out loads of bass given the right setup. And with more bass, the whole balance shifts toward thicker/denser/murky also thickening mids and making highs feel less present. Maybe the big cord feeds the Torii enough to maximize its bass/speaker relationship...the speaker/amp impedance matching thing. And within the tuning of Palomino's system and room, it was just ugly.
I think I recall that in the Torii design, the amp rides impedance shifts very very quickly, feeding more power as needed based on what would be to us imperceptible impedance shifts, and this contributes to its amazing speed and power response...Right???
Or perhaps the massive 25 watts, at least compared to Rob's SE84, makes a difference as well.
Or it may be that the SE84 would do a similar thing, but the break point into less bass (based on cable size) could be a smaller cable for the much smaller amp....Or maybe something to do with Rob's system/room tune. It would be interesting to see what a 16 gauge WE cable would do there.
Matchstick....there are a lot of theory discussions on the web on power cable materials, gauges, geometry, grounding schemes, etc, etc, including the "ideology" that all this is BS. I say ideology in this case because, to me, even the most articulate of the naysayers can't explain "the science" to my satisfaction as to why cables do not make a difference...certainly not any better than those who can explain why it does make a difference. And many naysayers give no real explanation, just belief, often without even having tried.
Not being able to hear these things is to me clearly based on other things than theory...system and room issues, hearing issues, maybe even "belief systems."
If the revealing transparency needed to hear subtler things is not there to begin with, at the source, it will never be there. And if it is there at the source, cables, vibration, speakers, amps, preamps, room frequency buildups or combing.....crossovers, caps, wires, resistors..........all of these vary in quality and signature, any one, or many combinations of these things could tone down areas of the original information on the recording that can reveal subtler sound differences.
And none of this proves that those who do hear these things don't. I know no one can tell me I don't hear what I hear any more than I can say someone who does not hear cable effects can hear them! But I can say without doubt, that in a very revealing system/room, the differences can be heard. I hear them all the time, as does my wife, and with her not knowing what I did most of the time.
I have read up on it, and there is plenty out there if you search the web. If you want more real theory and examples of experience, I would look more at those who find it works since we have more interest in knowing why and helping others to get more beautiful sound. There is even a forum called cableasylum. Audiocircle tends to have good forums.
And there are writeups from technical folks like this:
http://www.gcaudio.com/resources/howtos/powercords.html Personally I really don't expect science to spend a lot of time on cable/sound theory, or to explain strange things like fuses making a difference, the fuse direction even being a real choice in revealing systems where fine detail is not truncated or masked by system bottle necks. Realistically, with energy, we are talking sub atomic particle flows and interactions, areas where very subtle differences can easily change things. To measure the very, very fine, sub atomic aspects and interactions of energetic flow...with noise, conductance, resistance, phase, impedance, capacitance and so on, even dielectric interactions and "skin effect" make real differences in sound.....our measurements are obviously just not as refined as the human ear at this point. Not even considering more subtle aspects of sound we are not measuring, any one of these has potential for real sound impacts, and a few together even more.
I find the "science" interesting, and sometimes useful, but I don't need to know why I hear what I hear, enjoying "empirical" evidence from listening, and then learning/experimenting with how I can tune and refine systems based on this.
Here anyway, there is very little that is not noticeable enough to make the choice valid in the whole. I have been working in the last percents for a quite a while, and it is worth it to me, though it may not be to others.