Class D = Trash?

Did you listen to the amps before purchase? 

I may be able to add a very slight addition, to the volumes written here. Leave them on, or at least let them warm up well-longer than you'd expect for a solid state piece of gear. LIke, a couple hours. Think of tubes x2.

I'm a Jeff Rowland 501-pair owner. They were early serial number 501's and I had a catastrophic power event over New Years (2017) which cause both to crater. (let's just say, imagine your heart rate and stomach acid level when you realize both your Rowland amps are door stops....) ANYWAY - after a call to Jeff himself, and lest I digress, he's a true gentleman and engineer with SUPERB CUSTOMER SUPPORT even with amps bought used. Anyway: I had two new amp modules coming my way. The old ones were ICEpower 1000ASP, revD. The new ones were ICEpower 1000ASP rev J. Indeed, Jeff uses an input stage consisting of a Furman transformer, but the rest of the amp is the ICEpower ASP module - and I don't know, nor anyone maybe, if it's "Plain Jane" or "Jeff's Secret Sauce". What I can say about the "new versus old" is the Rev J modules (circa 2016 ish ?? I don't really know) sound better than the Rev D boards (circa mid 2000's?), and that's even before the Rev J's are really broken in.
Secondly...YES...break in time is crucial. When I bought my 501's, they'd been off for ~ year. I think they went through a break in period at that point, as they continually sounded better (and proceeded through the 'goofy midrange' 'echos in the mid bass' stages, then settled in). I'm now in that painful process with my new modules "brand spankin' new" - still not there yet (as I can't just let them run, right now: in May I will be able to. Family stuff. I digress, again) however I can attest to the break in time....but I want to add, and I haven't seen it posted yet - leave those suckers ON, or at least get them warm for a few hours before critical listening. 

To the astute reading this, you may have caught the dichotomy of "catastrophic power event" and "need to leave them on all the time". Yep. The need to leave them on led them to their demise. I have since installed an isolation transformer and voltage monitoring circuit. I do see myself turning them off for longer periods of non-use. Also - I will be installing PC-1's as another line of protection, as well as (hopefully) some sonice benefits, but they sure sound good as-is.

Secondly...YES...break in time is crucial. When I bought my 501's, they'd been off for ~ year. I think they went through a break in period at that point, as they continually sounded better (and proceeded through the 'goofy midrange' 'echos in the mid bass' stages, then settled in). 

Very helpful post. IcePower is definitely improving with their revisions. 

All this talk about break in is interesting. And talk about breaking in a used amp is even more interesting. I wonder if the amp is "breaking in" the speakers? Not much science behind that thought, but there's not much science behind breaking in transistors either...  

The best Class D I have heard does use an analog power supply (a large Toroidal trans with banks of power supply caps). In addition, if bass is of the utmost importance then an oversize analog power supply is a must. Don't get me wrong there are some very nice sounding Class D amps with a switching power supply but they seem to excel in the Mids and highs but lack bass to some degree or another.

....I can see a novel business opportunity here...a 'burn-in service' for D amps.

Send me your new D amps and I'll burn them in for you.  When I think they're ready, I'll send them on to you.  First come, first served, and be patient.

Don't gasp...either you can put up with it, or I will. ;)  Pennies a day....