Focal sopra 2/Gryphon Diablo 300 not good match

Focals can certainly be bright if poorly paired  I ran a pair of original Micro-Utopia's for years paired with a PP tube amp and never found them bright. I've only heard Gryphon in a show setting with their own speakers the sound was neutral but I can't even remember what model amp they were using.

Your cabling looks good too I have a Jorma digital cable and find it to be fantastic if I could afford their speaker cables I would have them. The sound is on the warm side of neutral.

I would say as others have suggested maybe mess around with speaker positioning also if the gear is new let it break in. But I'll also say don't kill yourself getting bright sounding speakers to sound not bright. Cut bait and move and certainly don't throw good money after bad.

WIth all Focals, minimize toe-in.

Having the speakers cross 3-6 feet behind your head is a good start.

How is your room? Do you have any room treatments?

What DAC you’re using with your N10. I also own N10 paired with EMM Labs DA2 and I can tell you it’s not N10. As others have pointed out Diablo is far from bright, in fact quite the opposite.

Moving to a warmer but very detailed amp or pair of amps might help.  I will admit, I didn’t by Focals before I started my company because I found them bright even driven by MC275s.

Are you in the US?  If you want to keep the amp you could move to a more neutral but detailed speaker like Raidho.