Ok, so I did open the XPA-1 Gen2 boxes, and installed them. First surprise was how pleasant and elegant looking those babies are,..!
In my setup, I kept the NAD M-12, used as DAC and streamer, and the Cary Audio SL-100 preamp, and listened to CD's through Marantz SA8005, then to Spotify, and some of my favorites LP's.
I have to say, first the Amp's front LED meters never moved from the corner at listening levels, as expected since my speakers power requirement never exceeded few watts,...But Man did the sound stage open up and the sound became full of details and clarity. To my ears, the music became much more present, and pronounced and engaging.
On some tracks I am very familiar with, I heard nuances I did not perceive before. I was dumbfounded,...to say the least. I was not expecting this coming from a nice Hi-Fi tube amplifier costing more then twice the xpa-1's pair.
I never expected the SS amps to sound better to my ears then the tube amps I have so far used for the La Scala II's,.. But to my surprise, I found myself liking the sound better, a lot better..
I may experiment later, by adding a tube preamp before the XPA-1's and see. Although I don't feel there is any loss of the warm sound the tubes delivered, while using those SS amps.
I may be wrong, but, to my ears, and in this setup, those babies are keepers.
Ty all for all your inputs.