Wilson Sophia 2--- VTL S-150 or Ayre V1-xe?

i would go with accuphase int amp- it will not sound bright at all!
good luck.

FWIW
I've only heard Wilsons with strong SS amps fueling them. Ayre mono's was the last incident. 400wpc. Transparent cabling. I WOULDN'T HAVE TOUCHED THAT SETUP WITH SOMEONE ELSE'S MONEY.

I do see them as very capable speakers and setup right probably will do exceptionally well... but they do seem to enjoy power from what I've seen online here and elsewhere.

I'd look for amp (s) that are very refined or at least one not agressive, with 200-250wpc or better.

Another note on bright sound might not be 100% many amps' fault. I doubt too many amp makers ever intend an amp to sound bright when they are designing it. many other factors do contribute to winding up that way and it's not ususally the amp which did it all by itself.

Then there's the budget too... BAT, Mac, Butler, McCormack among others.

VTL also still produces the little MB-125's. These mono's use the EL-34's , where as the ST-150 uses 6550's. The 125's may have the same power, and the Wilson may really sing w/ the EL-34. BTW, their prices are close, $5000 I believe. FWIW, the 125's also have the Triode mode like the ST-150. That said, I am not confident that either in Triode would be enough power. Perhaps it may be, but I am not sure. At the ST-150's price point, there is also some other interesting choices IMO. Maybe a C-J Premier 12, seen under 3K used, or a Quicksilver V-4.

CJ 350A would be very good. Don't expect best bass quality with any tube amp, trade off for midrange quality. Choice depends on priorities, if you want full volume and best bass go SS, if tube sound is priority then go for as powerful a one as fits budget. Large Audio Research are excellent but pricey. Big Krell probably best bass but also very high.