Focal sopra 2/Gryphon Diablo 300 not good match

I think that this speaker uses a Beryllium tweeter. I have heard tweeters of this type sound good, but this is not a material I would favor and usually dont like tweeters of this type. Experiment with speaker placement and tame your first reflection points to see if this helps. An acoustically bright environment with this speaker could be your problem. Wish I knew more about your cable. I dont think the Gryphon is your problem although tubes would probably help this situation. As Erik suggested, dont toe the speakers in one bit.

@joannism
For what it’s worth I attempted toe-in (and moving to other area of house to try in different acoustic environment) and nothing would shake the intensity in the upper midrange/ lower treble (aka "presence region");
I did not put thin cotton ring around the tweeter, though, a trick I have done before that works wonders for smoothing out response in this area;

In the end I sold them chalking it up to bad synergy and the fact that we all hear differently; I moved "back" to the smoothest sweetest most refined tweeter/ presence region  i’ve ever heard: Dynaudio.
Good Luck to you sir!

I'm with dpac996.  I have an older speaker presently in my system.  Mirage M3Si.  I have been building my new system for about 1 1/2 years and speakers are the last big category to replace.  The Mirage uses a metal tweeter, made of titanium.  Berylium is the common metal used now in place of titanium (like I said, mine are old speakers).  I absolutely did not want to move into a Focal speaker due to them using a metal tweeter.  I have always found Dynaudio speakers to sound just right in the midrange and the high frequencies.  And thus, my decision was made and now have a pair on order for the new Dynaudio Contour 60i.  They are due to arrive in the US during August.  Well anyway, that's my story.  The bottom line is that metal tweeters, especially if the room has a reflection issue, can be rather bright.  However, you described a very well treated listening environment.  I can only believe, therefore, that the metal tweeter is just not the right product for your listening taste.  As others have stated, we have all made mistakes or error in judgement.  We try, but ultimately move out of the product and make a change.  The pursuit goes on.  I wish you the best in finding and settling on what pleases you the most.

I had the exact same system you have.  Diablo 300 with N10 and Sopra 3s.   I did find it to be a bit edgy and intense with certain music but not like you are describing.   I had wireworld eclipse 7 and never used silver cables.   
I have EVO Scala’s with Octave gear now and absolutely love it.

I agree with others you may want to try tubes or class A amps.   Maybe change up the DAC as well.