Dyneaudio Confidence C2 II and Naim

Sorry I see you have the MKII's.

Keep the V80. My friend is driving sapphires with a V80 and black box. Maybe try a super black box. The Naim does pair well with Dyn's but there is a mid-bass hump. Octave has better 'control' in my opinion.

That being said I drove C2's with a Bryston B100 but decided to keep my C1's. In the end I got the V70se with black box. Have you tried KT90's or KT120's? Personally I like the Ei KT90 type2 over the TS KT120's.

Last are your C2's original or MKII? I upgraded to the C1 Signature and they sound much better at lower listening levels. With the originals the more you 'crank' them up the better they sound where with the MKII's they sound great at all listening levels as if they are more efficient.

It's either or...
Having incompatible to tubes speaker driven with high current solid state amp or easily driven by tubes speaker.
Both sides have positives and negatives.

IMHO "full HD" speaker isn't easy to drive with tubes.

I'd sell my speakers before I'd go back to solid state. keep the Octave and try a different, more compatible flavor of speaker..