Class D Technology

I think I can tell if the amp I’m hearing is Class-D or Class A.

In my experience, Class-D always makes me think, "hmm, nothing wrong. great sound!", and a good Class A makes me think "how you can do this? what’s going on here!". Cheap class AB’s has a typical glassy haze, but I have never heard the same thing with cheap Class-D.

I own Class-D from Spec corporation, it sounds clean, plenty power for 50 watts, taut bass, smooth high, compact size........, however I just  don't get connected to the music as opposed to 'tubes' amps
The magical sound is only from 'tubes' ... that for my ears

Great discussion and lots of valid points. I agree with those who feel Class D is not ready for prime time - great for PA and subwoofers but perhaps a few more years are needed for them to become viable to the majority of critical audiophile listeners. The black background many listeners can hear with Class D indeed suggests the heavy filtering is in some way affecting the audible sound. 

Class A particularly when no NFB used tends to have a somewhat warmer sound.

I have not heard Class D that I would call an inherent warm  sound, in fact not warm at all, however if a touch of warmth  is what one seeks a tube pre-amp upstream can help accomplish the goal.   The ARC sp16 I use with BC ref1000m amps does this to perfection through my very neutral sounding OHM Walsh speakers.   Tweaking of ICs and such can even make a useful difference here.

Hifi is like making soup.   You gotta toss all the right ingredients in the pot together to make it tasty for you.    Class D is a very good base to make your soup with IMHO.    Where it goes from there YMMV.

I have experience with many amplifying topologies, and I have found good and bad examples in each. Class D just happens to be one of the newest, with many improvements in the last generations.

100% agree with the following quote from an experienced reviewer:

  "Today experienced analog circuit designers have learnt how to harness switching tech (class D) in ways that please even those who initially wrote it all off as unfit for serious purposes should one be trained by class A amps of the transistor or tube variety. It used to be a sign of superior good taste to diss class D. Today it's become a surefire tell of sad ignorance. "