Do ClassDAudio Amps Have Proper Decay Of Notes?

I have one of the small class D amps based on the TPA3116D2 board and I bought it as an experiment. This is a very inexpensive amp so I hardly expect it to be state-of-the-art like some of the larger more expensive class D amps out there. It is my first class D amp and I am certain that class D amps (just like solid state and tubes) have different sonic characteristics based on the manufacturer and the technology used, so I would not attempt to lump them together. So I can only speak for the TPA3116D2 (common and inexpensive) and say the highs sound rolled-off and the timbre/decay of the instruments do not sound realistic. This is when played through high sensitivity horn speakers and comparing it to other much more expensive gear. It sounds polite and pleasing to the ear, but it is not convincing with regards to the instruments. Again this is just an opinion of this one amp and I'm sure there are much better sounding class D out there, you just have to spend more $$ like anything else in this hobby.

Every component & every connection is important in audio if you want realistic playback. Trivializing the power amp-speaker connection will lead to only trouble for you. Neglect it at your peril.....

+1!

Low level detail (which includes decay) is a common problem!

My recommendation is to avoid difficult loads for the amp- with any amplifier including class D, you can see the distortion climb in the specs when you drive lower impedances and you can hear it as a loss of detail and increased harshness. Put another way, if you can reduce distortion in the amp, it will sound smoother and more detailed. Good Luck!

Dont rule out the importance of the amplifier as well as associated componemts as others have mentioned. I have been using Class D amps for.some.time now as the heart of our hybrid amps. In a system, everything matters. I prefer tubes in front of them. If not a preamp then a good tube buffer makes a big difference. Just be careful of the type of load you put on the ClassDaudio amps and stay away from plannars.
Other than that, i am very happy with Class D which is why i chose to use them in some of our products. The Class D Audio products are exceptional for the money.

Thanks for your input gentlemen, sorry I haven't replied for so long, I haven't been on this site. Just to clarify, I absolutely don't discount that the power amp is crucial to the sound. My throwaway comment was more to do with how insanely expensive they are compared to other components when you're on a budget, and don't alter the sound as much as a line stage or cartridge. But yeah, crucial.
Atmasphere, my speakers are an easy 8 ohm load @ 90db. They sound great with my current 3.5w tube power amp, but I listen to so much alt rock that I miss the filled out bass I had with my previous solid state monster, which I only got rid of because it went out to 200khz and I had oscillation problems with my preamp. The ClassDAudio goes out to 35khz, do you think this is far enough to avoid the ringing issues that switching amps have? I haven't read a bad word about ClassDAudio amps (other than that you can do better if you spend $5000 etc) so I'm guessing the guy has nailed it, although some people thought the top end was recessed, but who knows. The only other thing I'm worried about is the gain at 30db might be overkill for my speakers. My preamp only puts out 0.775 though. Mmm. Thoughts welcome.

Class A to Class D and back again.

I have owned a variety of Class A and AB solid state amps and after a couple of auditions I thought I could improve on my situation with Ncore, NC1200 Class D monos.  After a year, I found the Class D amps simply did not sound as natural to me as my former Class A and AB amps.  

Some might describe what I hear as a deficiency with "decay" but I usually describe it as a deficiency in micro-dynamics and, a flattening of the soundstage, or lack of depth/dimensionality, compared to better amps. They also seem to lag behind in the high frequencies and how those can create a sense of space, venue and infill between performers.  The end result could be described as the sound of individual musicians cutting tracks in a recording booth that are then put together to make music, instead of a band playing together and the music being recorded at one time.  To me the Class D amps were just not as real sounding, which is similar to the opinion of the reviewer at Mono and Stereo in his review of the Mola Mola Kalugas, that you can find on-line.

End result, I am back to a pair of 300 wpc Class A monoblocks and find that they sound much more natural and enjoyable in my system....although they are not quite as cool looking, cool running, or as quiet.