Oh come on guv'nor - I worked at a Linn/Naim dealership (itself a huge subjectivist minefield) and left the retail side retail in 2004!!!! That's nineteen years and almost a third of my life ago and believe me, the journey's been a rocky but enlightening one since and I ain't given up learning/unlearning more just yet!!!
All the sensible objective 'stuff' and realisations coalesced many years later when I DID do some unsighted comparisons and realised that level differences usually account for any perceived changes within reason. I do remember the odd occasion when I 'thought' I heard a difference and yet nothing was changed from A to B - other tales of the same thing told here, so I'm not alone in deeply un-trusting my ears, especially now with them as they are - the HD25SP on-ear headphones do seem to inject high frequencies better when I'm not wearing the hearing aids for some reason and they're still ok if 'lively' when I am, but that's a different subject
I mention the Linn Black interconnect as to itch a scratch I bought a used one recently to see if it really
did appear to change the sound of the CD player I wanted to use it with

level matched but sighted and A then B I could swear it
appears to lighten the tone ever-so-slightly and emphases 'acoustic' a little more than the home made RG59 based cable I was using. Of course it's not scientific in any possible shape or form and on the face of it, these cables look to be straightforward screened coax types and nicely soldered up into the custom but basically competent generically sourced plugs which you can have customised with labels or whatever if you order enough. This well used cable does what I think I need it to do, but if anyone in the US has a set (unlikely to be any/many Linn electronics owners here though), perhaps Amir could give 'em a go.