What to upgrade on $3,000 budget

Thanks very much. I went back to the old interconnects which are less revealing. But I think I'm missing something significant because I was told the Audioquest Diamondback was neutral and transparent and that transparency is causing the harshness.

"I was told". I see a problem here. It's very common. It happens when someone has an eye on some more of your cash. It starts when someone questions how you could possibly enjoy your 'less than perfect sounding system' or encourages your own questions. They have a fix (cables usually), which often leads to an unpleasant change in the sound you've been enjoying. And on and on and on...

How can an 'Upgrade' or an 'improved' anything, cause a system to sound worst?? It's just beyond my ability to understand.
Cheers

Transparency does not cause harshness, transparency reveals harshness. It's like looking out a window, your old interconnects were less revealing, they covered up for the unpleasant view.

The new interconnects cleaned the window so now you have a clearer vision of an unpleasant view. There are two things that you can do here, either cover the window back up again or work on improving the view (system).