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
I tried the Nord Hypex NCore NC500 One UP monoblocks in a bid for more power. However even with the switchable opamps, including one that operates in "Class A", they were no comparison to my real Class A amp and were soon removed. Sounded cold and heartless. They weren’t right for me but seem to work for others.
as georgelofi has pointed out I think class D strength lies in sub-woofer applications. They do a remarkable job in my Golden Ear Triton One’s.

What I don’t understand - but am rather certain you guys do - is that in the case of the Triton One, the class D amp is rated at 1600 watts. The speaker is powered with 115V AC. That would mean over 10 amps even if 100 percent efficiency which it isn’t. I have both (2) speakers on the same breaker. Why haven’t I blown a fuse? Seriously, doesn’t ohms law here dictate that the amperage would be (if played loud) greater than 10 amps per speaker? I feel they are drawing very little power and don’t understand how that could be given the 1600 amp rating, unless spec provided by GET is inaccurate.


georgelofi you are correct about switching frequency being teh key to even better Class D amps in the future.

Have you listened to any good quality class D amps or are you judging solely on technical interpretation?

Fact is the good ones sound very good today, as good or better than most. There is plenty of reviews and such published that support that.

I can vouch for it as well FWIW.

Thing is I am over 50 and do not hear to 20khz like I know I could when younger. So I am not the best one to judge what’s happening at the highest frequencies in detail.

In general, its something of a good thing not to be able to hear up to 20khz because there is often more noise and distortion at those frequencies than music.

Check the audio frequency music chart and one can see little music happens at the highest frequencies people can hear. It’s mostly "air". That’s part of music granted but since most audio involves a compromise of some sort, this is a reasonable one.

All I know is I cannot concretely fault anything in the sound I hear from my Class D amps with any speakers up to the task of handling all they can deliver. Most people would be thrilled with them. They are the quietest amps ever, with a totally black noise floor. At least that’s what I hear.




gdhal I think one of the things switching amps excel at is delivering power and current for very short periods of time which makes for excellent detail and transients. Its a very important aspect of music that often distinguishes great sound from just good. Power and current specs alone as published probably do not indicate an amps ability to deliver power and current quickly and efficienctly for very short periods of time when needed.

One way this is refelcted uniquely with the Class D amps I own and use compared to others is detail and articulation of the bass in particular. It is leaps and bounds more articulate and detailed than any other amps I have owned or even heard. When I first heard it, I was shocked thinking my bass was gone when in fact it had leaped to an entirely different level not heard prior.

My impression is tube amps tend to be a bit softer in this regard (which some may actually prefer) and class a/b SS amps often just miss it altogether.

Class A amps, tube or otherwise are historically the ones that probably do this best, but that is changing.....
Lots of great responses. When switching frequencies are 5x higher than today's, what will be improved? Will that prevent the saw tooth waveform challenge? Or prevent the need for a low pass output filter?

What makes today's class D amps sound cold and dry? I have experienced this firsthand with an ICE Module that I once owned.

Mapman alluded to a totally black noise floor. I also experienced this with the ICE module. So far, this is the only benefit other than efficiency & power output that has been discussed and can be attributed directly to the Class D topology. Or maybe this noise floor issue is unnatural and sounds are being cut off prematurely by not allowing for decay?