Regarding the EVO 400 possibility, while I couldn't find measurements on it many PrimaLuna power amps have particularly high output impedances, even for tube amps. If that is the case with the EVO 400, given the speaker's rising impedance in the upper treble region (see Figure 1 of Stereophile's measurements here) the result of that pairing may be an over-emphasis of the upper treble region, which sounds like the opposite of what you are looking for.
Regarding the XA25, which I own, I second the comment by three_easy_payments. And especially his suggestion of pairing it with a tube line stage. The XA25 is very transparent, and pairing it with a very transparent solid state line stage may be too much of a good thing, given what you are trying to accomplish.
Good luck. Regards,
-- Al
Regarding the XA25, which I own, I second the comment by three_easy_payments. And especially his suggestion of pairing it with a tube line stage. The XA25 is very transparent, and pairing it with a very transparent solid state line stage may be too much of a good thing, given what you are trying to accomplish.
Good luck. Regards,
-- Al