Pass x250.8 vs Boulder 850 vs Spectral DMA250

@Bo1972, you hit the point, and I'm lucky: I will have enough time to test those amplifiers, not only a day, but sure I want to:
- get emotion, the only parameter I personally consider when all other parameters are substantially correct
- be absolutely calm ! :-) very high risk of compulsive buy!

Seriously, an hi-end journalist said that a correct equipment evaluation is made on the first 3 minutes and the next 3 months.
I was asking for suggestion because coupling tube preamp and solid state amp could be very critical but I feel to follow this way, because I hear the potential of this solution.

@Ebm, thanks, an audio reason to do so without any doubt.. will be welcome.. :-)

I loved my x250.5, but my xa60.8s were in another league.

Check out the pass xa.8s

@Skootb if you take a look at my system pictures, there is no space to place on it two monos like the XA... I will double check again.

"@Zd542: I partially agree with you about the possible degrading of SQ using different solutions due to a couple of facts I experimented in these days: the C2500 sound quality is very high compared to some friend's SS preamps and it is (suprisingly for me) neutral, and I'm not a fan of Mc gear.
Second, a good match, in my experience, can be completely unexpected as this little class A ss amp that changed my vision, even with its limits, and convinced to me to try the solid state way without Mc output autoformers (slam, nuances, etc.)
I'm coming from a Vitus RI-100 it was a good integrated amp but not so fast and with a little roll-off on bass area."

I wasn't suggesting that you would have a bad match using your McIntosh preamp. I don't see your system sounding bad because of it. I think it may not be the best match to some of the amps you are looking at. Also, the preamp has a huge impact on the overall sound of the system. All the pieces in the system have to work together to get the best possible sound.

I would choose for Pass Labs directly. But...that information is just personal and totally not interesting for you.

Often you know what you prefer or like in a very short time. A good remark is a big smile on your face. :)

Before owning it, you need to enjoy the search for your ultimate amp.......have fun....Bobby