What's causing the highs to be rolled-off?

I finally achieved the fullness, detail, and bass-weight I want from my system.

My system:

Blue Circle BMPH integrated-solid state /Audience PC (to FIM outlet)
Modwright Sony 999ES /VH Audio Flavor 4 PC/ Furutechs
Raytheon tubes
Acoustic Zen Matrix Ref II (single end)
PS 9.0(power supply for Modwright/ tube rectified)
Black Sand Violet V1 PC
Raysonic CD 128 (VH Audio Flavor 4)Wattgates
EH 6922 tubes
Acoustic Zen Matrix Ref II (single end) and Blue Jeans XLR
PS Audio Premier /PS Audio Statement SC PC
Reimer Wind River GS speakers
Acoustic Zen Satori cables
HSU vtf 2 mk2 sub / FIM outlet/ PS Audio Ultimate Outlet
Earthquake Supernova Mk IV sub

Both my sources are connected to the Premier. BMPH to the wall. The problem is the highs are rolled off. What do you think is causing this? A few days ago I cleaned the Audience PC connected to the BMPH with deoxit- I wiped it off but did not use anything like alcohol to clean off the deoxit. Could that be causing roll off in the highs? Or could it be the PS Audio Statement SC power cord which just finished break-in after 2 weeks of playing. I'm considering trying a DCCA cord on the Premier in place of the Statement SC.

Thanks for your feedback.