Going through forums people ask advices only on tube pre amp to combine
class D amp probably for the fact of the colorations of tube and some
sterile class d amp they own.
Tube preamps are not used to add colorations. They are used to avoid them as many solid state preamps sound bright. Most solid state amps do too, but class D is altogether a different animal and does not have the same artifacts as traditional solid state (so they don't usually sound bright). In fact some class D amps are quite neutral- far more so than traditional solid state. Since solid state preamps have lagged behind class D in this regard, that is why many people resort to tubes.
To be clear here, when I use the word 'neutral' it encompasses 'musical' as well, since we are talking about low distortion that is consistent at all frequencies (traditional solid state tends to have increasing distortion as frequency is increased). When distortion is **properly** controlled then the circuit will be both musical and neutral.
If you must go solid state, I would be looking at either a Benchmark or Pass Labs.
