Break-in of a Class D amp?


I'll spare everyone the "brand tribe" debate, and keep my question/details generic.

I recently had to have my 2ch ClassD amp "serviced" by the manufacturer.  Yes, it's an ICEPower derived unit.  I'd been SUPER happy with it for well over 18 months, until one morning when I heard a buzzing coming from inside the amp itself.  I took a video, poked the manufacturer, and they voluntarily opted to fix it for me.

Fast forward a week, and the amp is back in my stack.  But something is amiss. 

I can tell they wholesale replaced the entire ICE module, as the "power up" delay from standby is "different" than before, and it seems to exhibit less overall "gain" than prior to repair.

But the most disturbing thing, and one that literally smacked me in the face... was the lack of high frequency authority.  While there is a soundstage, and lows are not an issue... it's missing all the "presence" and "life" in the top end.  I have tracks that I can play that elicit EMOTION when I queue them.  All the detail and fidelity is like, muted.

The previous board had hundreds of hours of time to burn in, and boy I exercised it.  Is this what I'm now encountering?  Or has anyone out there experienced this situation?  

I would normally just knuckle down and "grind out" hours of "work" for the amp... and not come here asking for advice... but the fidelity difference is so striking... that I can't get over it.

Thoughts?
rabbottmke
Was at least 100 hrs for mine and probably more like 200, although part of that may have been breaking in my ears to the quieter background and more clarity at the extremes.  Sort of made the upper midrange seem shallower at first.  Did you listen to a different amp while yours was being repaired?
@tmcclintock Negative.  I went cold turkey for a week.  Kinda made me really appreciate how much I do need/love my setup.

Well... done with work for the day.  Time to "exercise" the amp a bit... and get some more burn-in done.
My experience, and it is shared, is that ICEpower ASP modules don't like to be left off for more than overnight.

Leave them on for about 4 days and they'll recover.

Best,

Erik
So as a follow-up to all this discussion, I'll leave some notes.

1)  Need for burn-in of the ICEPower boards = True.

I spent a few more weeks with the newly refab'd unit, and indeed it DID improve.  So much so, that I almost hesitated with point #2 below.

2)  The incremental difference between an ICEPower based Class-D amp, and a McIntosh MC-312 was much more significant than I expected.

While stewing with the "newly refurbished" amp, trying to break it in... I contacted my local dealer.  I requested an A/B between MY ICEPower unit (not one he'd had on his showroom floor) and a MC-312 using the same system.

While doing the demo with a few of my select demo tracks in hand, I immediately could sense an enhanced "decay" in some instruments, and for some reason, even MORE separation ... compared to my amp.

So Fast Forward a few months of waiting in line for my dealer to get a drop shipment from Binghamton... and a couple more months of critical listening... and I do admit... "you do know where that money went".

(could not help the movie quote...)