@blueranger
Since you lived with (and presumably enjoyed) your previous incarnation of the same amp for so long, and since you have indicated the new amp has brought further improvements over the former (already well-liked amp) then I suggest you quit listening so hard and simply enjoy what you are hearing for a while before being critical about the parts. The dedicated line and improved power cord should have moved you in a better direction. If you want to try something, put your former preamp in the system and listen (assuming you still own it). I have found that preamps can have a significant effect on how a system sounds so maybe running the new amp with the former preamp will provide better context on the sound of the new amp.
I'm still hoping for that little extraIt sounds as if the new amp already surpasses what you heard from your former amp so what further improvements are you hoping to hear? I am asking because I have owned amps that "checked all the boxes" but simply didn't give me what I was hoping for. So, I believe each listener has intangible preferences that push their buttons when they are right. I have had gear that gets me most of the way there but not quite.
Since you lived with (and presumably enjoyed) your previous incarnation of the same amp for so long, and since you have indicated the new amp has brought further improvements over the former (already well-liked amp) then I suggest you quit listening so hard and simply enjoy what you are hearing for a while before being critical about the parts. The dedicated line and improved power cord should have moved you in a better direction. If you want to try something, put your former preamp in the system and listen (assuming you still own it). I have found that preamps can have a significant effect on how a system sounds so maybe running the new amp with the former preamp will provide better context on the sound of the new amp.