Break in period

+++ No respectable engineer would deliberately design an amp with a significant drift in electrical response characteristics over 100's of hours +++

Really? Are you an engineer perhaps?

I am also somewhat amazed as to why you equate the phenomena of burning-in to something that is deliberately engineered? That is quite absurd. I replaced couplers in many-many amps. I most certainly did not do it to create the burn in phenomena – that is just a function of the cap I used – but I have almost always witnessed the caps settling down/burning in.

Simply because the bottom-of-the-barrel, cheap crap components used to manufacture Sony, Pioneer, Denon, Yamaha etc. does not exhibit this behavior, does not make them superior nor does it make their designer more 'respectable'. I can assure you, the Sony, Denon, Pioneer etc. engineer doesn't give a rats ass if his component is subject to burn in or not.

I opened an Onkyo DVD some time back and had electrolytics for coupling caps that probably retail for less than 1c each. Sure, you won't hear them settle in. They sound crap before settling, and equally crap afterwards.

I replaced the couplers in said Onkyo with $5 (yes, 5 bucks) worth std BG 16v 47uF caps. The owner is now beside himself at the improvement. And yes, he did notice the BGs burning in over the first 100 hours also, but I can assure you it sounds a lot better than the stock unit and then some.

Because your equipment does not exhibit burn in does not mean it doesn’t happen ... my $9.99 transistor radio also did not burn in. (Does that mean it better than my Audionote?)

Regards
Paul

A bit harsh, Paul.

It is my impression that even inexpensive gear benefits from break in.

Harsh but not unduly. Shadorne has missed few opportunities (in the related posts I've seen) to repeat his break-in-is-all-in-the-mind nonsense. It clearly takes a lot to penetrate HIS mind (changing his mindset is obviously not in the cards) and the frustration in trying to keep him from spreading this mischief can become quite palpable. Right, Paul? :-)

Drubin. I suspect that all gear is subject to burn in. However, I have little experience with inexpensive gear and as such would be silly to argue against someone that has.

I am also somewhat amazed as to why you equate the phenomena of burning-in to something that is deliberately engineered?

I assure you that engineers do have to worry about these kinds of things when designing equipment and not just the performance of the device on the day it leaves the factory.
Often the part selection and design criteria are heavily influenced by the desired products useful life span. Nobody wants a "lemon" out there that hundreds of customers complain about; the cost to make a manufacturing recall to get equipment to perform properly as originally specified to customers; the cost to reputation.