There is no “free lunch” when it comes to reproducing a clean signal from the power amp to drive speakers. There is a very good reason a very well respected amp designer like Nelson “Papa” Pass has a large cache of mostly Class A designs available. As Papa says: “Class A amplifiers sound better”. It takes energy to get the best possible sound.
Engineers have been trying to tackle the amplifier efficiency problem for generations, with some success. The various topologies of Class AB, Class B, Class D, Class H, etc. are all attempts at getting more output power to the speakers while drawing less from the electrical source. For example, engineers at NAD, Luxman, Carver, Soundcraftsman all have a scheme where there are different “voltage rails” that switch when a large power demand is made on the amp by the speakers.
While these are all neat engineering tricks from the minds of clever people, they are not perfect. The downsides of these various approaches are that they involve some “switching” of the amplifier to create and transfer the waveform to the speakers. Class D without question has a lot more switching going on than most other topologies. A linear power supply will help this out some, but certainly does not eliminate them. The amp design itself works on switching, so they will always be there.
I’ve listened to a lot of Class D amps (I also owned a Rowland Class D amp for a bit), and to me, they all fall short of true high fidelity reproduction. They remind me of a upper range mid fi AV receiver. The Class D amps I’ve heard to date have a much different sonic signature from something along the lines of a Papa Pass Class A amp, for example. That’s not to say that at some point they catch up and become indistinguishable from a good Class AB amp, but do not think they are there yet. My personal preference is Class A solid state, followed by tube amps.
Now, some folks will obviously disagree with this, and that is fine. We all have our preferences on sound reproduction, and what one person overlooks a particular aspect as a non issue, another person will dislike that same aspect of the reproduced sound. (E.G. Vinyl vs. High Resolution Digital Audio debate).
Here is link regarding Class D sound:
http://www.hificritic.com/downloads/Class-D.pdf