While I have a Mdac modded just like Steven's I wasn't aware of it 'burning in' on return from John. It certainly sounds different stone cold to how it sounds after five minutes of being on, but that's all.
Which is considerably different to how it changed over the first week of initial ownership.
Max you can ignore the posts on the first pages by Martin, John, Alan, myself and others if you like, but it is an incontrovertible truth- some components, and as a result designs, do burn in. It's just a plain old measurable science fact.
If you doubt it the next time I build up another Paradise phonostage I will video the input offset meter swinging about at various times over the first 70 or so hours. Like a pendulum coming to rest over time the bias eventually levels out with absolutely no intervention from external sources whatsoever.
I can well see Keith's point about it being funny how things always burn in to be better than worse. However that's just the nature of electronics. They either reach a steady state and continue on in this fashion until such time in the distant future as they slip gracefully out of spec. Or they explode in your face and kill you. There's little in between. it's just a shame that there's so much shit talked about burn in, that so many people have no grasp of what might lie underneath, and that many dealers are just great big f-in liars who will say anything and use any trap to make a sale to the unsuspecting and gullible.