Class D - A Fork in the Road

Eric,

There are dozens and dozens of A/B comparison between Class D amp vs other topologies, easily researched.  

At Axpona a couple of years ago I got a brief master class in amp topology from Ralph Karsten from Atma-Sphere who for ~40 years has produced really excellent tube gear.  During our visit, I heard his Class D monos driving Spatial Audio speakers, similar to those I owned, and the sound was fantastic, just as fine as the sound with my tube amp and Class A/B amp.  Ralph said that his company sells more of these monos than all of his other gear!

I borrowed an Orchard Audio Starkrimson Class D amp and it was fantastic in all respects.  The seminal work that Mr. Putzey has done with his topology shows where the leading-edge thinkers are and while Ralph has his own design/implementation approach, Class D amplification is clearly and firmly the ascendant technology.

I applaud Ralph for his incredible contributions in the audio world and, more to the point, his selfless contributions on so many threads on this forum.  I relished the half hour he spent with me at Axpona; he sees many paths to supreme enjoyment of music and has himself provided the electronics for many to enjoy that satisfaction.  His Class D mono amps are SOTA and in comparison to similar quality Class A/B amp or tube amps, very affordable.      

OK, so I've come to the conclusion from all the responses that it's not the type of tech, but rather the implementation of the design. So that would mean to me that they're pretty much the same sounding if designed by competent people.

@koestner how many folks have actually compared the two offerings in a meaningful way? Thus able to actually answer your question. I say few. Very few. Not enough to provide a conclusive responsible assessment. 
Class D Audio (GanFet) offers an at home trial period. Take them up on it. 

https://classdaudio.com

although I think you misunderstood some of my post

@ericrhodes1 I'd be interested in knowing what it was I misunderstood. For example, do you know of a GaNFET amp that is made in China and sold by a Chinese company? Or is that an example of something I misunderstood?

OK, so I've come to the conclusion from all the responses that it's not the type of tech, but rather the implementation of the design. So that would mean to me that they're pretty much the same sounding if designed by competent people.

@koestner This is no more the case than it is with conventional amps. You are probably aware that harmonic distortion is something all amps make. Further, you are probably aware that our ears use harmonics to tell the difference between sounds, like the difference between a trumpet and a violin. 

When an amplifier makes distortion, the harmonics it makes ride on the waveform and are visible on an oscilloscope. So they are readily available to the ear as something that can be interpreted as a tonality.

This is why tube amps are known for their smooth sound (and are still around, despite being declared 'obsolete' 60 years ago...) and is also why some solid state amps have a reputation for being bright and harsh (which is part of why tubes are still in business). 

So even though quite competently designed, you can still hear differences. If the designer is aware of how important the harmonic spectrum generated by the amplifier is, he might thus design the amp to not make objectionable distortions (such as higher ordered harmonics, which can cause an amp to sound harsh and bright if they are not masked). 

Well that can of course be true when comparing say a 300B tube amp and a decent SS amp. Those harmonic distortions give the amps their signature sound, but in the case of these 2 types of Class D (GaNFET and Purifi Eigentakt) where each of the amps are designed to have the lowest possible distortion percents, including harmonics, I would think they would sound somewhat similar.