"Let’s play with the "burn in" crews heads.
If you think about it, all the optimum adjustments are made at the factory after the amps been on for a while, maybe an hr if your lucky.
If thing change after 600hrs then those optimum factory adjustments have just gone out the window and need to be redone again.
So it’s either out of adjustment because of aging, and therefore not optimum, or the factory needs to have them on for 600hrs before they are adjusted and sent out to the shops.
Either way if things change they would be out of the original optimum adjustment.
Cheers George"
I understand what you're trying to say here, but that's really not how it works. When a designer is building a new product and makes changes, the component gets broken in before they listen to it. For about 20 years now, I've been evaluating prototype's during the design phase for several manufacturers. I break in every piece of equipment they send me. Sometimes I'll see the same component 10-15 times as changes are made. That means I break it in 10-15 times.