but I think it’s possible to demonstrate the probable existence of something before we are able to provide proof by measurement
I don't, but would be happy to be wrong.
and to obtain agreement of its existence by demonstration.
But in that case, the demonstration would be a form of measurement. Remember, listening is itself measurement, its just like any measurement for the results to be of worth it must be done with prior design and care. And to be repeatable by more than one person.
The problem with HiFi of course is it’s subjectiveness. Two people listening to the same thing don’t necessarily hear the same thing.
And two rulers measuring the same object will give two different values, that doesn't mean the measurement or the ruler(s) are of no value.
Little known fact, coherent thought can destructively interfere with itself leaving no thought at all, that’s why I prefer incoherent thought.
Mains cables polarise opinion as so many aim their arguments at the notion that it's all about supply of power only. The argument goes something like "there's miles of wire before hand so the final metre means nothing" ergo, it make no difference. Or something along the lines of "if the mains cable makes a difference, your equipment is broken". Technically it is at a gross level but the reason they make a difference is that there's a bit more to it than that.
The vast majority of HiFi is single ended and the various boxes have ins and outs that are not galvanically isolated. Add to that the earthing of these items shunts noise in their circuits and chassis to ground via one cable; the earth wire in the mains cable. Add into the mix that this "signal cable" is wound in close proximity to the power which is not only supply currents but reactive currents from the transformer rectification and there is a very non-linear situation. Unsurpringly, mains cables and their construction make a difference to the sound of yer HiFi. This is a closed loop system usually from your distribution strip to the various pieces all plugged in.
I would wager the effects of all this is measureable but quite how those measurements would translate into what it sounds like is anyone's guess. This is where the pseudo technobabble comes in which kinda ruins the facts surrounding the starting point but manufacturers have to seperate their wares from one another but it also gives the subject a bad rap.
Studio gear is of course sensible; balanced so not referenced to ground, sopmetimes also galvanically isolated ins and outs. As for PA gear, it's operating at so far away from the nosie floor, who cares about mains cables as long as they do the basics; supply the power.
Some folk couldn't care less about the small things as is very evident in the replies. As long as it does a bunch of stuff right, they can't be bothered about the small stuff. Life's too short etc and fair enough.
My aim was to see if I was was bothered about the small things in relation to my gear and I found the level of effect I heard meant I couldn't be bothered as the diffrerences weren't worth it. Bigger fish elsewhere. But then maybe that is also because my gear is, after the cartridge input, balanced and galvanically isolated ins and outs with fairly benign PSU configurations.
Very good points there, thanks. I gave up on one source as, even though it was a class 2 device (double insulated), the noise floor lifted when it was connected and the sound went hazy on all sources for want of a better word. I didn't think of changing cables (mains or interconnects) as I had transformers to hand, but it would be an interesting experiment. It was my wife's karaoke machine and she is happy with it, so I left it alone - probably a unique problem on this forum