If an amp had to be 'broken-in' the designer would know all the parameters and they would be measurable, predictable and definable - and if they were - guess what - it wouldn't be shipped out unless it was 'broken-in' - or the spefic instructions for 'breaking-in' would be in the manual - including the number of hours/days/weeks, etc. - including what 'changes' would be noted.

but any manufacturer of high-quality equipment is going to be damn sure that 'out of the box' is the sound PLANNED FOR.

All graduates of the course Logic 101 - should subscribe to this.

Amen!