Thanks to all for replying,
The speakers are mounted, each one, in a dedicated foot, just 40 cm from walls. I can't do better with that. The living room does not me allowe a better configuration, although I have separated them from the walls one meter and still the sound is amalgamed.
When I listen to a well recorded CD (Patricia Barber or other jazz music) sound is good but when I go for my rock records (Cure, U2, ...) and there are plenty of instruments the sound is like an amalgame, everything is mixed, there is no separation of instrument. I do not think the problem are all these albums (I miss high frecuencies also ). I have taken some of them to an average shop of music and played them in a budget dvd player/ampli with speakers less expensive than mine and the sound was clear and I could recognized the strings from one side, the drums too, keyboards, etc...
I know tha V2.0 UP is no the best amp of the world, I jsut thought that an amp giving more current and able to "move" my speakers at low volume could be that one. Yes, I lke music sounds good at low volume as I spend most of my nights awake while I work at home. I think my speakers have a medium/high sensibility (89db) and should deliver a good sound at low volumes. That is why I thoung the problem was the ampli. Of course I know very well that a cheap B&W will sound better with my marantz becase they match very well but , as I said, I'll be difficult to sell these speakers and I think they are good, juste need the right amp.
It's a shame I can not post in here a picture of my HIFI chain, I have a pic in my computer but I do not know how to doit.
Many thanks again
victor