Marco, I think you have to bear in mind that you have a very good, very expensive valve power amp. As do a lot of people here who use valves. But most valve power amps are highly compromised in a lot of ways, compared to a cheap solid-state amp. I have heard some really poor examples and some that were listenable but really far too coloured to be classed as 'high Fidelity'. So the frame of reference is everything, really.
Current Lash Up:
TEAC VRDS 701T > Sony TAE1000ESD > Krell KSA50S > JM Labs Focal Electra 926.