System upgrade advice


My current setup is okay but the high end is too shrill. Some may call it sibilant. Its driving me nuts. My setup is:

Proceed PRE preamp
Rotel RB 1080 2 ch. amp
Oppo BDP-95
Paradigm Studio 60 v2

It does seem that the Paradigm tweeter is where the issue is since I also connected them to a Yamaha AV. The Yamaha toned it down a bit but the whole sound went down a notch. I'm considering replacing them with maybe some used speakers around $2.5k (pair) like some B&W 804s. If I did that, would I have totally out classed the Rotel and Proceed?

Looking some general advice or similar stories. Tired of my ears bleeding

Thanks.
vjb
The Proceed PRE Preamp is the culprit and is known to lean towards sounding bright, even a reviewer of the Proceed Pre mentioned not to couple this preamp with highly revealing speakers for example like horns.
Bo1, the Kappa 100's are not in the same league as the Rens which are classics.
All I care about is the sound. I owned a pair & could happily live with them even coming from my Magico S5's.
Thanks for all of the input.

It has been a few years since I purchased all this equipment so I forget what the speaker wire is. It was from a high end audio store and as I recall, it was a couple notches up from the Monster cable stuff ("Silver" something or another). The interconnects are AudioQuest Green ($40 each). Are interconnects something I should consider changing? If so, what would be a good price point considering the rest of the stuff?

I will try to connect the Oppo directly to the amp and see what that brings.

I'll have to look into what a tube buffer is.

Thanks again.