Break in time that extends to months or maybe even years!!

Well first off if the gear cannot be enjoyed right out of the box then sorry but you bought the wrong gear. 

That said, everything improves with time. But its not like break-in is all that's going on. 

There is also warm-up. Some things warm up fast, others can take hours. Solid state gear is famous for needing to be left on 24/7 in order to sound its best. 

Then there is magnetization and static charges. Playing music, the rapidly alternating signal gradually and over time can magnetize regions within wires and components. Static electricity can also build up. As a result transients become smeared and grainy and the noise level increases. This happens gradually and most never do anything about it. Most don't even know about it. I do, and address it every session. 

The last big one is power. Sound quality improves along with power quality late into the night. 

So any given night you have the sound improving from this complex mix of warm-up and charges and power. Add break-in to that if the component is new. 



 

No one's gear sounds any good prior to 5,000 hours.  

It's a huge selling point in some circles to buy gear that is extremely demanding.  The speaker that requires megalithic amps to sound good. The amp that needs $10K power cables to bring out the best performance.

Yes, I've heard break in, and no, I've never heard anything take more than 4 days.

@douglas_schroeder   No, that's just your gear, Doug..;0)

Dream on companies can not tie up resources to break in stuff.This is high end audio if you do not like this take up photography.