Class D Technology

call me stupid but what do you mean by a "Output Filter" ? A L/C for you amp? Thanks, I am thinking about a Bel Canto but have never heard them.

You might want to hear them first. They are not for everybody. Most people feel that they are incredibly clean sounding with great control of the bass. However, some people also feel that they sound lifeless in the midrange compared to high end linear amps. Of particular importance is the module that is being used. Of less importance is the brand name responsible for putting the module and power supply in the case and tweaking the input stage to create a house sound. Tube preamps can help with the lifeless sound, although some prefer that sound. Good luck.     

     seanheis,

     I thought that anyone wanting to learn more about class D amplification may want to hear from the horse's mouth,inventor of UcD (Universal class D) and the much newer NCore class D devices Bruno Putzey,, from interviews he has given on the links below.    




http://ultraaudio.com/index.php/feat...audio-part-one

http://ultraaudio.com/index.php/feat...audio-part-two


     He discusses many interesting specifics about class D in a manner that is articulate and informative without needing to be an electrical engineer to understand.  I found his discussion of the feedback loop (" there is no such thing as too much feedback") and switching frequencies ("A reasonable switching frequency for a class D amplifier is just under 500khz") especially relevant to this thread's content thus far.

     Please read these attachments.

Thanks,
 Tim

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.