Focal sopra 2/Gryphon Diablo 300 not good match

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.

While I am not sure that I agree with d2girls that we necessarily want to strive for a flat sound signature, I do think he/she makes an excellent recommendation that you may want to buy an eq.  In fact, the Schitt Loki is only $150 and users here give excellent reviews noting no degradation in sound from the unit.

D2girls; my confidence 30 and 50 measure very flat; Dynaudio designed these in their mega expensive Jupiter Lab; they are like a precision instrument that does not emphasize any particular frequency, so I’ll have to disagree with you; Some speakers are just voiced one way or another with actual program material however; Trust me; if the recording is live and well balanced the Dyns will portray that about as perfectly as possible. There is no roll off in the tweeter; 
I would be willing to bet most folks prefer a sound that emotionally connects them to the music, which by definition is the embodiment of emotion; our ears are not microphones and our brains are not oscilloscopes; I think Nelson Pass said that and I happen to agree; Cheers all and enjoy the music!!

I had a similar experience with some lesser Focals (profile 918) a few years ago. I picked them in a shop demo room over everything else I heard that day and I’d even taken my own amp and CD player in for the demo. Got the Focals home on loan for a week and just couldn’t get them to sound anything less than excruciating in my room. I ended up with Thiel CS1.6 so it wasn’t too much detail that was the problem. I‘ve head other Focals since at shows, mostly with Naim amps (which I use), including some large Utopia models and never found them enjoyable despite the merger/takeover which presumably means Naim amps will be among those used for voicing the recent models.

I have Focal Sopra 3's, and have never heard them sounding 'bright' except in an untreated room with reflective walls.

In my 13'10" x 19' room, which has a wool rug on a wood floor over a concrete slab, absorbtion at sidewall reflection points plus 88 sq ft of bass traps, they sound very well balanced across the frequency range, coherent and detailed without ever being bright or harsh.

Driving them with a Linn LK280 (recapped) amplifier, Linn Kairn preamp, Bryston bda-2 DAC.  Source is a Raspberry Pi 4 streamer running piCorePlayer, USB output to DAC.