??? WHY WHY WHY ??? Class A vs Everything Else

Class A has positive attributes but you do give up stuff like high power often needed by some speakers and of course there's the heat. Like the real world it's different compromises which vary with your taste in sound and your system.

By the way you often see reviewers citing a preamp is class A. It means they don't know how preamps are designed. All preamps are class A because it's easy on a differential preamp since there's so little current involved. And single ended preamps have to be class A: their topology can only be class A.

I might add that as above all single ended amps are class A. But almost every push/pull class A amp eventually goes into class B at very high output. And the class A portion goes down with lower output impedance for solid state amps. The only exception I know is the old Mark Levenson ML2 amp which doubled power down to at least 2 ohms and remained in class A. And it was the biggest 25 watt amp I've ever seen.

Class A-ish tends to sound the best,,,

Here’s a more technical discussion on it from the engineers at Schiit Audio

https://www.youtube.com/watch?v=_rSQCqqTk4E&t=1534s

But, if your HVAC kept kicking on in the summer and the noise floor in the room went way up...oh well...

They all sound great to me but lately I have been a fan of Class D/GaN amps. Crack out the class A stuff in the winter. 

All the amps these days have such good components in them that they all sound much better from amps a decade ago unless they cheated out on the components.i amp roll alot and that's half the fun.then there is the sandbox some synergy is better with some components.the gain,feedback ,impedence,ect all have to get along in the sandbox. When the force is correct from star wars it's exciting.nurvana class a a/b d and h .love it all. Now let's talk cables that should get the party 

I built a Hiraga Super 30 Class A amp. It is the amp I listen to most, just does everything well. Lots of detail, without being fatiguing. Amazing 3d soundstage, with clear imaging. Rich mids and tight bass. Is very responsive to upstream components, showcases differences in the front end. Works well with most of my speakers, though it’s too much with my Cornwalls in the low end - my Type 45 plays better with those. 
 

One thing I noticed, is how well it plays at low listening levels. 
 

I would love to get my hands on a GanFet Class D amp, so I could compare the two. I have class A tube and solid state (single ended and push pull of both). Several different types of amps based on different output tubes. 
 

They all have their “thing”they do well. And depending on what I’m listening to, speakers and amps will be swapped in and out.

But is the Hiraga I keep coming back to.