Thanks for checking your power conditioning setup. My thought was that it may be current-limiting, have bad wiring, or might be affecting the impedance or voltage level from your mains.
I'll add that 150 hours break-in on speakers is low. I'll also add that the Audience AU24SE IC's offer a laid-back and organic presentation with no hint of brightness, (fantastic cables, BTW). In the review of the Sim W-5 amp that I read, the author felt the highs were slightly rolled-off (in a good way), so I don't expect your system to ever sound bright. With that said, give the drivers more break-in time.
Let's see what happens when you change to a different amp. You could also try substituting the IC's. Try using RCA cables and see how it affects the sound.
I'll add that 150 hours break-in on speakers is low. I'll also add that the Audience AU24SE IC's offer a laid-back and organic presentation with no hint of brightness, (fantastic cables, BTW). In the review of the Sim W-5 amp that I read, the author felt the highs were slightly rolled-off (in a good way), so I don't expect your system to ever sound bright. With that said, give the drivers more break-in time.
Let's see what happens when you change to a different amp. You could also try substituting the IC's. Try using RCA cables and see how it affects the sound.