I don't have any direct answers to your questions, but a couple of observations that might (?) help:
I'm using my 805Sigs with a Cary 303/200 CDP, Cary SLP98 preamp, & a C-J MF2500A amp, & am very happy with the combination. So replacing the Sony with a Cary player might be a good idea.
Also, I found that putting the Sigs on great stands (instead of the b&w stands) almost completely cured any brightness issues.
I'm using my 805Sigs with a Cary 303/200 CDP, Cary SLP98 preamp, & a C-J MF2500A amp, & am very happy with the combination. So replacing the Sony with a Cary player might be a good idea.
Also, I found that putting the Sigs on great stands (instead of the b&w stands) almost completely cured any brightness issues.

