What class of amplifier has the most high definition sound ?

soix, I concur; we are not in disagreement. We may vary on what we feel the degree of contribution the amp (whatever type) and the system contribute, but both are critical to desired outcome, and everyone will have their favorite genre of amp. Absolutely, the quality of the amp in the chain is critical! And, people will feel strongly about the genre of amp they think is superior. 

A. Nothing is better, except maybe single ended class A.

Give Spectral a try. There are a number of reasons you may find it rewarding. Resolution combined with macro and micro dynamics. Utterly uncoloured. They are fanatics; and Professor Johnson has never been influenced by money or short term gain. It’s a very unusual company; a pure pillar of truly high end audio. 

Hi there
We can get the most natural sound from class A amplifiers. They have "soft" distortion spectrum and they are stable for pulse signals because of stable power consumption. But they produce some specific problems too. Open my page in LinkedIn (Vladimir Benkhan). There are couple articles about it and a description for simple class A amplifier.

The amps that shine in class A are the pre-amps .