So if you are hearing this change, you better speak to Frank, you must have a DEFECTIVE unit, there is no drift or change in solid state electronics, one of the reasons for it's existence. I have several AVA units there is no change, there is no drift, nothing happens if I leave them on for 2 weeks, or one day or 5 hours, it always sounds the same. That's called good design, electrical stability. Have you not heard Frank say many many many times there is no need to beak in, nor is there any changes. Does your computer change over time, didn't think so, if it does, there is a PROBLEM. Why is electronics different in audio components? the electrons don't know any difference, the components ae stable in DAC's or computers, or pre amps etc.
Right now I have at least 9 AVA units in use in my system, nothing changes, why would YOUR one DAC change?
Oh great, another saviour swooping in to tell us what we are or aren't hearing so that we don't have to hear or think for ourselves.

This is YOUR opinion festuss and that is fine, just don't ram it down our throats as if we were gullible young newbies who haven't been in this hobby for decades. Sure, your opinion may be shared by others and even Frank himself. However, there are others who have a different opinion based upon their own hearing in their own system. Surely you aren't so arrogant as to believe that these people are all wrong simply because their observations differ from yours? I haven't seen anybody state (in this thread) that electrons change, or any of the other implications you made ... they have simply conveyed what they heard. You are also wrong that it is just one person. If you had bothered to read the thread you would have noticed my post on the previous page describing changes that I heard in an AVA Ultra DAC as it burned in or settled in or whatever else you want to call it. And no, I was not pre-conditioned to hear it. In fact, knowing that Frank has stated in the past that there are no audible burn in effects with his gear, I was expecting no changes whatsoever. However, over several listening sessions over different days, with no other system or room changes, the DAC sounded dull, closed in, congested, vocals were pushed back into the mix. Still thinking that AVA products have no burn in effects, I really did fear that I had made a mistake in purchasing this DAC and pulled it out of the system with a view to selling it off. Because by nature I am methodical and thorough, I figured it can't hurt to throw it into my headphone system for a while (where the same traits were observed). I gave it about 160 hours then installed it back in the big rig, with the view that it would be no different and I would then sell it. Still NO changes to system or room. BIG difference ... much better dimensionality, separation, voices were much better delineated and brought forward of the backing instruments, the (relative) lifelessness and flatness had gone. Performance is superb. Had I been even more closed minded to the possibility of burn in effects I would have sold it and never known what a truly good DAC it is. It has performed in this way ever since, over multiple listening sessions (ie. no further changes that I can hear).
So, no I don't know the scientific reasons for what I heard (and don't really care), but they were obvious despite me actually expecting the reverse. I don't recall you being there so please don't try to tell me (or others) what I heard as all it does is to erode your credibility in my eyes. Similarly, I won't try to tell you that you have poor ears or a poor system not to have heard burn in effects. I have no idea of your background, ears, system etc etc and am happy to accept that you have heard no such effects from AVA gear.
Perhaps I should also point out that I don't claim to hear these effects in all new equipment though I have heard them in some others. Sometimes I "think" I hear something but wouldn't swear to it. Other times it is quite obvious, as in the case of the AVA Ultra DAC.