Class D Technology

I’m not sure if anyone has covered this (I didn’t read all 8 pages), but if one is chasing greater efficiency than Class A without sacrificing as much fidelity as Class D tends to do, Class G and H amplifier tech would seem to be the best choice. For those unfamiliar with this tech, voltage is constantly varied across multiple supply rails to the output transistors, allowing current to flow based on the constantly changing demands of the source material.

This greatly improves both efficiency and headroom, and perhaps most relevant in this discussion, allows the amps to run in pure Class A bias for a relatively large portion of the listening range with massive Class A/B power reserves for handling peak demands. Arcam (Class G) and AudioControl (Class H) are the most accessible options for this tech, though I’m sure there are others out there as well. About the only downside is that it’s an expensive design compared with more traditional tech, but as we head into the future where efficiency requirements are becoming more stringent, this is the best option I see for preserving audio fidelity. Just my .02. :)

-David

@erik_squires and @noble100 ,

I'm glad you both have found systems that you are happy with, and you are certainly correct in that there are some great Class D options available on the market - I do not believe I stated anywhere in my post that Class D in universally inferior to A/B. What I did state is that Class D designs tend to sacrifice fidelity in favor of efficiency, which is true in most cases. Are there exceptions? Sure, though that's not really what the OP was asking; his question was not if the best Class D designs can compete with Class A/B, it was:

"If it weren't for efficiency & power, would there be any reason to own a Class D amp? Do they beat Class A in any other categories that count for sound quality?"

And while audio quality is somewhat subjective, I think you're going to be hard pressed to argue that even the best Class D amps will rival the best Class A amps on the market. I brought up Class G and Class H as being potentially better options in the ongoing search for increasing efficiency while preserving fidelity, which from a sheer technological and design point of view, is hard to argue with when it comes to reproducing full-range audio. The only downside is cost, as it's a much more expensive technology than Class D, and that may well be what prevents it from ever becoming a mainstream option.

Anyway, I've no wish to start an argument with you or anyone else - I was simply trying to share my thoughts on the subject based on my experience as both a long-time enthusiast and owner of a home theater company. 

Cheers,

-David