Solid State Power Amps

There are many excellent suggestions so far.  If you are casting a wide net;

I just updated my preamp (to Audio Research) and as it burns-in my biggest impression is that my Ayre Amp (V5-xe w upgraded capacitors: 300 W) sounds great - voicing is as-good-as/better than many more expensive SS amps that I have heard in shows and at showrooms: I do NOT feel the need to upgrade my amp to make the ARC preamp sing.

This morning AG has only one Ayre Amp, the higher-line V-1x, for sale (at The Audio Room, below $5k). Refreshed w new Caps, you may find you saved $20K.  

I have no affiliation w Ayre or The Audio Room.

For 25K I would go with the MC1.25

Amp vs Preamp.....Right now my Borresen X-3's are singing. $10,000Tube preamp going into...wait for this....the New NP1 Power amp ( 55 watts into 8 ohm) Van Alstine amp. ( first run is sold out)....What a musical magic amp this is for $1,199.....always spend More on the Preamp than you do on the Amp and Tube the pre with SS on the Amp. Nirvana.

I would recommend the solid state Bryston 14b3 with your tubed Primaluna 400 preamp. The Bryston is very uncolored and neutral, just producing the music quality it is served, nothing more and nothing less. Very powerful with unlimited power at 600w at 8ohms. It can deal with any speaker. 13 grand.

Used Boulder 2160 if you can find one. Good luck!