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

Thanks for the link Tim. This quote tickled me.

Much the same with converters. If you know exactly what to look out for in a chip, you can find chips that are really suited for use in a $1000 product that, for the price, will offer fantastic performance, simply incredible value. Speakers ditto: You wouldn’t believe the performance of some $10 drive-units, but if you’re hung up on exotic cone materials, you just won’t discover those.

+1, erik_squires.....

savdllc,

     You stated: " 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."

     This statement implies that class D requires you to sacrifice significant fidelity when compared to class A/B.  As a user of various decent quality  class A/B amps exclusively for about 30 yrs (beginning with Adcom and then McCormak and  most recently Aragon) before trying various good quality class D amps (beginning 2 yrs ago with a budget ClassD Audio SDS440SC  then an Emerald Physics EP-100.2SE and currently D-Sonic M3-600-M mono-blocks), I can assure you I never felt I was sacrificing any fidelity with class D.  

    With all 3 class D amps I actually experienced quite the opposite; immediately noticing significant improvements in noise level, bass response, mid-treble fidelity being very similar to class A/B with my initial budget class D and clearly superior to my former class A/B amps with my admittedly better quality most recent class D amps.

     I know there are many here on Audiogon who have discovered  switching to class D is all gain with honestly no pain.   I'm concerned that comments like yours, and other posters earlier in this thread, may give readers the false impression that switching to class D involves some sacrifices in sound quality.
      I want to make it clear to everyone considering a switch from class A/B to class D amplification that these sort of comments may have been accurate for some early lower quality class D amps but are definitely not valid for current good quality class D amps.  

     Once you've experienced the extraordinary improvements a good recent class D amp will make in your system, you'll begin to realize how inaccurate, no longer relevant and simply untrue these types of comments are.    

     I can only rationalize these sorts of comments by assuming that these individuals have obviously never auditioned a recent good quality class D amp in their system or anywhere else.  Although it's possible  they're just parroting comments they've heard years ago about early examples of class D. 

     I'm grateful I ignored these class D myths and opted for an open minded home trial and suggest others do the same.

    Concerning class G and H, I have never heard either but I'm interested in hearing them.  Being an extension of class A and A/B amps, however, I would expect them not to have the same advantages of reduced weight and size that class D allows.

Thanks,
  Tim