AVA Van Alstine SET 400 amplifier -- burn in?

i personally dont want to get opinions from members on how something should sound out of the box or after a few days of run time. 
  i think that when you do this, you are setting expectations and if those expectations dont happen , then one is disappointed .       

 how something sounds in another members system is not going to be the same as another member as there are to many variables to consider (other equipment  / cables / room, etc. )

one should be able to know pretty quick if something is a keeper or not.

@riley804 Your caution is appreciated.

I'm confident enough in my abilities to listen for myself. But one help for me in this hobby has been to hear about what others have heard -- especially if they have heard *any* change at all. Same as when I go to a new city -- I ask friends about what they heard, saw, enjoyed there. It primes me to be alert to things, but it doesn't force me to prejudge things. Anticipation and conditioning are different for me. Sounds like you feel differently. To each his/her/their own.

@hilde45   Years ago I auditioned this amp.  I paired it with Magnepan 1.7's.  On paper I thought this would be a perfect match.  During the 100 or so hours I listened, it's character did not change much.  I found it a bit flat and lacking in bass.  In fairness, I did not have their matching preamp (which was discontinued after a very short production run) so some blame might have been placed there.  After that I auditioned a Marantz Reference intergrated which I found much more pleasing to my ear--more subtle, smooth, spacious, with shockingly good bass relative to the AVA.  Really wanted to like that amp but could not deny what I was hearing.  
Also of note were a couple of small scratches and a buzzing transformer.  So back it went.  Cancelled the preamp order as well.
This is not to discourage you.  Systems are all about synergy as you already know.  But more to your question, I did not note it to change much in character over 100 hrs.

@corelli Thanks for your experience. I don't know how long it's been out. I cannot find reviews for the amp prior to 2018, so I suspect that "years ago" meant within the last three years. Unless it just didn't get a review for a while after it was released. 

I won't be driving Maggies, but I admit that it's capacity to drive something like Maggies was in the back of my mind. I am driving Salk speakers with it.

@hilde45 Forgive my haste.  I actually auditioned the  FET Valve 400 amp, a step above the SET 400.  Good luck, look forward to your impressions.