Burn in question and evaluation before burn in

I have found that gear which sounds off/not right/bad etc.., will not change enough over time to make it acceptable.

All I can do is refer to the examples I've already given. If you don't accept my experience as believable, that's OK. It obviously differs from the path you've chosen.

I was a believer of burn in before, much more so now than before. When I started the thread two days ago, I noticed my new preamp turned from good sounding to intolerable after about 30 hours of playing. I played several my most familiar music, the treble was so bright and thin, and the bass was absent, that I had to check all my set up and connection to see if anything wrong; I found nothing and concluded the change in sound was most likely due to a certain burn in stage, I was not sure though, and hence posted my thread out of my curiosity.

After reading Albertporter's posts, and especially his prediction on burn in stages on transistor based design, I was more assured of that what I heard was not just my ears playing tricks on me.

After another 20 hours of play time since my first post, sure enough, the bass came back, and the treble became more focused and detailed. Actually, I found the bass is now actually a bit too much, I am hoping it would become slightly better controlled. Anyway, those are dramatic sonic changes in the last few days. I would easily dismissed the preamp if I only heard it during its worse burn in period.

Come to think of it, I seldom owned brand new equipment, and maybe that was one of the reason I did not experienced such dramatic burn in change before. Also, although the preamp was not totally new, the main board was replaced with brand new one, and that the unit I purchased came with brand new Linn silver interconnects and power cables, which I also put into use at the same time, all would attribute to more burn in changes.

If my current experience about burn in is jusitified, I would not judge a brand new equipment just because it does not sound good right out of box.

Maybe I'm not being clear? I agree wholeheartedly in burn in being significant overall. All I'm saying is that a sow seldom transforms itself into a goddess.

If my current experience about burn in is jusitified, I
would not judge a brand new equipment just because it does not sound good
right out of box.

That is exactly what the manufacturer and salesman would say. Just be patient -
eventually it will sound right. I prefer gear that sounds good from the "get go"
and barely changes with use - "robust" would be the right word or - perhaps -
"radio shack".

Burn in could certainly be conveniently used as an excuse by salesman or manufacturer when facing complaint about their product.

Re design with or without components with significant burn in drift, I do not have sufficient technical knowledge to decide which way is better, I am sure it is arguable. However, I think it would be very helpful for manufacturer to educate sales and the consumer how its products would change sonically after burn in. So for example, if I know a product would eventually be sounding brighter/darker than when it is brand new,then I have some fact to rely on in deciding if this equipment would be good for my system without keeping it forever, or well past the allowable return period.

On second thought, it is probably too much too hopeful for any manufacturer to do so. There is just so many variables, and there is no financial incentive.