What class of amplifier has the most high definition sound ?

The Audia Flight Stremento Mk2 is class AB is one of the best made  and best sounding solid  state amp made. 

sacresta what does pure sound mean? 

Do you mean uncolored, dynamic, bass slam, treble extension.

There are uber high resolution amplifiers Solution, Spectral, very low levels of coloration

and there are warmer reference amplifier lines Vitus, T+A, Darhtzeel, Dagastino, Pass. 

Generally speaking, class A will have the lowest distortion and thus the 'PUREST SOUND'.


Generally speaking, because execution can play a pretty big role in the results.


BTW, the **kinds** of distortion can be more important than the amount; 0.005% THD won't do you much good if its all higher ordered harmonics (which is often the case with THD figures this low) since the ear uses higher ordered harmonics to sense sound pressure. For this reason the ear has to be extremely sensitive to higher ordered harmonics and so is more sensitive then the best test equipment!

Recently, class D has begun to show promise as an amplifier technology that can lack the higher ordered harmonics. When amps don't make higher ordered harmonics, they can sound very relaxed with great detail, such that you can listen to them all day. This BTW is the foundation of the tubes/transistor debate...

So if one is being pragmatic, there really isn't a one-word answer to your question.