Tubes or stick with S/S

Been happy with my Graaf GM50B integrated. 

I use a few different amps with my Klipschorns, from a 2.5 watt Miniwatt through to a 20 watt Weston Acoustics Troubadour. You won't need more than anything between those numbers with your Cornwalls.

@OP, 

I own the Primaluna Dialogue HP integrated.  It's great.  I do, however, think, you might want to try a SET amp.  You do not need much power to make those C-Walls sing.  I should know.  Why? Because I have Klipsch Forte IIIs (in addition to less efficient speakers) and they sound better with a SET amp than the Primaluna, in my room.   

You could start with a Dennis Had amp (find him on eBay--he's the former owner of Cary Audio).  Wolfe (above) has one.  https://www.ebay.com/itm/STEREO-TUBE-AMPLIFIER-INSPIRE-by-DENNIS-HAD-300B-TRIODE-SINGLE-ENDED-AMPLIFIER/153463991221?hash=item23bb2aabb5:g:j7sAAOSw~PVcwdjC

I built the Elekit 8600 300B amp recently reviewed in Stereophile.  In a few nights you can have SET nirvana for ~$2K--if you do all the upgrades.  https://www.stereophile.com/content/gramophone-dreams-27-elekit-tu-8600r-amplifier-kit

If i may butt in here for just a moment and derail this topic momentarily to ask a question because it has to do with tubes. I just switched out my Callia DAC for the MHDT Orchid which has a tube output. So far it sounds REAL good (not yet broken in) and i am happy i made the switch. Problem is, i do not have volume control or very little via Tidal. So, my question is, is it possible to use (temporarily) the callia which has volume control or say a Mojo DAC which also acts as a preamp without it bypassing the Orchid? And lastly, i was thinking about getting the Schiit Freya preamp, it has tubes so would that kill the hybrid sound i now have or enhance it? Any comments, good or not so good would be helpful...       

I’m Single-Ended Triode. I also like mechanical watches. I have a SS amp down below for the family system. Like a mechanical watch - it wins before turning it on. I am enjoying my wife coming up to my cave to hear the music she can’t hear on the SS. To be fair, I spent 10X as much on it. Just like my watches.

Edit - add:
@15W/channel - I am near field, but never go above 30% dial.  I have run Martin Logan 35XT and not Watkins gen four (wow).  No issues with power.  Pushing ribbon, I understand I need more power.  So not pushing ribbon.