Whether or not "burn in" is subjectively valid is for the individual to decide for him/her-self. I've never seen any objective proof for this claim and I would find it difficult (but not impossible) to believe that any respondent here has done sufficiently rigorous testing to validate such a claim. And I believe that anyone who could reliably distinguish between virgin wire and "burned-in" wire (e.g.), and prove it, could make a small fortune with such wagers. I know that I'd place a bet. And while they're establishing that they could also demonstrate that wire has unique electron flow characteristics for each direction. This type of thinking reminds me of how I felt about my first car when it was just washed and waxed. It always seemed to run better when it looked better. Of course, this remains, like so many things audio, a matter of opinion for many. When in fact, the truthfulness of the matter can be tested to satisfaction for anyone willing to accept the results. But, I also realize that words on a screen represent no proof what-so-ever. So, when applicable, for the purposes of civility. We can agree to disagree regarding this. I have to exclude tubes which have been "burned in" so long as to be considered well aged. Their properties may have changed enough to be audible.
