Just a quick update on the D225.
Keep in mind the amp is essentially brand new and not burned in at all.
There is no part of the spectrum that is exaggerated, it is smooth from top to bottom, like I haven't heard before. Even at really low volumes the amp sounds full. It sounds the same whether I'm at 1/8 volume or 3/4 volume, just louder or quieter. More so than any amp I've ever heard. The Nuforce Ref 9 V2 was the previous best I'd heard at this. The D225 blows it away.
This amp is absolutely, positively, dead quiet! Like, amazingly quiet. Like I have never really heard a quiet amp before in my life, quiet. Maybe because it's so quiet, details come thru like I've never heard before. By detail I don't mean the typical, more treble, etc, I mean, background sounds, breaths, movements on instruments, the recording environment. On Jason Mraz's I'm Yours, which I listen to all the time, at the beginning of the song there's the sound of waves hitting the shore. I've never heard any hint of these before, but with the D225 they were as clear as day. On Jack Johnson's Banana Pancakes, in the beginning there is the sound of rain falling. Normally it sounds like a little trickle in the background. When I listened to it this morning, I actually paused the song because I thought someone had turned on the water in the bathroom above where I was sitting. That's how pronounced it was, it sounded like it was literally raining out the window.
At this point, I've only listened for a couple of hours total, so that's all I have for now. But it is clear this is the best amp I've ever heard and it's not even burned in yet.