Break-in ?

jchiappinelli OP
I realize that almost all audio gear requires break-in before things reach their full potential.

Don't let the "snake oiler's" tell you electronic components need weeks, months, years, to "burn in" they don't most stuff has already been taken to operation temperature for a couple of hours to be "adjusted to spec" (bias, dc,etc etc) at the factory.  Electrolytic capacitors take the longest, a couple of hours will see them "properly polarized" if not they are dud caps.
If the those components took months and years to "burn in" then the factory "adjusted to specs" figures will be out to blazes and need readjusting, when you "burn in" for a few months.

The only components in audio systems that "really" needs "burning in" (I think "bedding in" is a better term) and will sound different are the "mechanical devices", tweeters,mids bass drivers, in the speakers will change a bit over time because their roll-surrounds, cones will change compliance, (get stiffer or softer) over time. Also the stuffing inside a speaker will compact over time and "could vary the acoustic damping a little. Even phono cartridges, their cantilever suspension components vary it's compliance over time.

Cheers George    

break in takes a long time, potential shows early. 
digital way passed 200
turntable (bearings, motor..30)
cartridges more than 50
amps way passed 300
speakers 100+
cables...hm (especially power cables)
The higher you get the more you wait.

No one (with the exception of ebm) has addressed my original question. Either responses have been that break-in periods are not really necessary or posters go on to list the reasons for and required time for breaking in various components. I'm not questioning the need. The owners manuals for several components i have are specific as to the break-in periods required for their equipment to reach full potential. The question remains  why don't manufacturers bed, burn, or break in their products as part of their provision. This should be especially true when it comes to products commanding 5 or 6 figure price tags. 

J.Chip

The question remains why don’t manufacturers bed, burn, or break in their products as part of their provision. This should be especially true when it comes to products commanding 5 or 6 figure price tags.

I said it before in so many words, "they are" and adjusted to specification at operational temperature at the factory.
If they "burnt in" anymore after weeks and months, all the adjustments made would drift also that were made at the factory, and it would then be out of spec, and sound worse
The manufacturers don’t say for you to bring the device back for re-calibration after it’s "burnt it" do they?

Speaker drivers are the exception, as they are mechanical and do change "burn in" from new.

Cheers George