Pass x250.8 vs Boulder 850 vs Spectral DMA250

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

08-15-14: Maz65
@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.
Maz65 (System | Threads | Answers | This Thread)

Yes Maz65 a tube pre to a solid state power amp/s needs to be thought about, as it's just like impedance matching a passive pre to a solid state

A tube pre's are generally much higher in output impedance than a solid state pre's, therefore they need amp/s that have higher input impedances, 47kohm or higher would be a good start, there is no problem with tube amps because they are usually 100kohm input.

But your Sonus Faber Elipsa Red to get the very best out of them demand an amp like I outlined above, one that gives current all the way down to 1ohm, and that means solid state BJT (bi-polar) output stage that can almost keep doubling it's wattage down to at least 2ohms if not 1ohm.

I can think of even better ones, but out of the three amps you gave us to recommend, only the Spectral has close to goods I've mentioned above.

And it is tube preamp and passive preamp friendly as it has 100kohm input impedance.

Cheers George