Break In can be real depending on what you are breaking in. I think those who claim otherwise simply haven't had the experience of change - and that doesn't impugn them - they have had gear that didn't change.
After several mods involving black gates caps, for a gross example, I can testify that they DO break in and the sound does change. In my SCD-1, the change at about 150 hours was for the worse - much worse - so bad you think "it's broken," but after another 100 hours, it comes back full and good.
I also had a tube amp change as I listened - it wasn't subtle or slow - it was as if someone had changed a perspective knob (there isn't one!)
Bob Wood
http://www.GreatHomeTheater.com/stereo/html
After several mods involving black gates caps, for a gross example, I can testify that they DO break in and the sound does change. In my SCD-1, the change at about 150 hours was for the worse - much worse - so bad you think "it's broken," but after another 100 hours, it comes back full and good.
I also had a tube amp change as I listened - it wasn't subtle or slow - it was as if someone had changed a perspective knob (there isn't one!)
Bob Wood
http://www.GreatHomeTheater.com/stereo/html