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Class D Technology

So I get the obvious strengths of Class D. Efficiency, power output & running cool which allows for small form factors. I also understand the weaknesses somewhat. 1. Non-linear & lots of distortion that needs to be cleaned up with an output filter. 
So my question is, 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?  
seanheis1
mapman's avatar
mapman
15,679 posts
 
I think were already seeing digital/Class D integrated amps make significant headway. The technology is so good already (low noise floor and distortion compared to separates) that I see no need for a separate pre-amp these days anymore quite frankly. When time comes to replace my current pre-amp I will likely just go with a Class D integrated of some sort based on my experience to-date with digital Class D integrated in my second system.
atmasphere's avatar
atmasphere
7,068 posts
 
Speaker cables would be a very poor antenna.  Since wavelength of 500kHz switching frequency is 600m a typical 2m cables would be 1/300 wavelength antenna.  Usually antenna becomes rapidly ineffective below 1/10 of the wavelength.
That's true, but in order to meet EU directives, UL and a host of others, the speaker cables are effective enough that the issue has to be addressed by any classD amp producer. In fact it is speaker cables that are mentioned when the issue of HF radiation is brought up in the design papers.

However, its so easy to address that I regard it as a non-issue. As I do the switching noise of SMPSs. The only reason we don't use the latter in our OTLs is the cost of custom SMPSs- its a lot cheaper to use traditional supplies!
guidocorona
4,114 posts
 

Hi seanheis1, as far as I know, preamplifiers cannot be implemented in class D... I have been told that their topology is the equivalent of class A. However, Preamps with regulated SMPS do exist... ANd the ones I have listened to are rather wonderful: e.g. Rowland Corus and Criterion, Rowland Capri and Capri S2, and the preamplifier section in the Continuum S2 integrated.


G.

guidocorona
4,114 posts
 

WOops... You are correct George: Theta Prometheus is indeed based on full NCore1200, not on the lower end NC500 module... My bad!!!!


G. 

kijanki's avatar
kijanki
3,575 posts
 
Maybe we will start seeing Class D preamps then...

Perhaps.  Delta-Sigma D/A, A/D converters, SACD and DSD are already class D.
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