What makes Sopra a good pairing with this amp?
Focal have a reputation for being detailed which, I think , can be interpreted as overly bright. This might be why @mofojo says they are a good match for Tubes. They have a wonderful sweet spot at certain db and mine were sensitive to placement.
I run my Focals 926s with a Mullard tubed pre and class A/B power. I have always been interested in hearing them with tubed power.
Years ago I heard are pair of Dynaudio fronted by Octave Audio tube amps at Rocky Mountain Audio Fest. Also a very impressive combo. Can’t remember the exact model of speakers but they were moderate sized towers. Basically hotel room config.