Amp and speaker matching.

My experience with Dynaudio drivers tells me they like high quality solid state amplification and the Contour 3.0 is no exception with the impedance dropping to 3.4 ohms. This is of greater concern than the 86db sensitivity rating.

I run a pair of Totem Mani-2's (4ohm/85db) and had previously auditioned them with several tube amps. The closest to what you're thinking would have been a Jolida 502B (60W rated/85W max) There were a couple of others, a Prima Luna Dialogue 2 and a Synthesis (Italian but sorry, can't remember the model) both of which were of lower power. Although each of these amps did drive the Totems nicely in some areas, my overall opinions kept me looking for another tube amp without the deficiencies I was hearing. The sound was always, well, too thin if that makes sense. In the interim I pushed them quite satisfactorily with a W4S STI500. Then I found my Cary CAD-120S MkII (120W Ultra/60 W Triode) with which I have been thrilled. My search has ended for now. Having inefficient, power hungry speakers made for a long, sometimes frustrating search, auditioning amps that many (especially sellers) told me would pair well with the Mani-2's. I ended up where I always suspected I needed to be...with a tube amp of higher output. FYI- I listen to broad range of musical styles, 85% vinyl/15% CD. YMMV. Good luck.

I have driven my Maggie 3.6's (86db 4ohms)with my VTL ST-85 in triode mode which is 40 watts with no problem. It is hard to answer your question unless you try the combination or someone here has tried it
Alan