Why would anyone want class AB amp when class A always sounds better ?

Orpheus10, I don't have such a hearing as you imply, but my ear is quite sensitive to some aspects of a sound. 
Let's not transform this thread into tubes/transistors debate. Sure, ultimately tubes rule.
That's what we are trying to talk about - designs without compromises or almost without compromises. Heat, space, cost, look - this is all BS, just certain side effects. Done right it should always be full Class A design. And since Class A requires high level power supply, that's an additional advantage, that's where it all starts - with a power supply.

Audio Research amps run A/B and top of the line ARC are the best I've heard. I'm sure there are better, but they are the best I've heard.

I think balanced and unbalanced is also significant because balanced interconnects are not affected by long runs.

Anyone in the NYC area - Northern NJ area who would like to hear the differences, send me a PM.  I would be more than happy to show you differences in equipment - Class A tube, Class A SS, Hybrid amplifiers, Direct Heated Triode components, etc.  I'll even supply the pizza.  Bring your amp if you like!

Happy Listening.  

@audioman58That being said , inside the Quality of the parts have much more to do with the final result of the sound.

I would have normally agreed with your statement but last night hearing an OK to good parts preamp it was so close in sound to the better parts model we build I began to wonder if paying for custom transformers, resistors, capacitors, separate chassis, etc. was worth it.  So close it was confusing to us and made me think that we have now come full circle.  Still point-to-point wired and good parts but so close.

Happy Listening.   

@michaelc2020
If you are eve in the NYC area let me know  I can should you a pure 1 watt amp on a pair of Klipschorns that sound simple beautiful.

Happy Listening.