System very bright after adding Mcintosh amp

So, I recently added a Mcintosh MC7205 amp I purchased off of audiogon to my system. Im using a Marantz Sr8002 as the pre/pro and have b&w speakers (683 fronts, htm61 center, and 686 rears)

Anyway, I've noticed that recently the whole system is abrasively bright. It sounds like whatever I am playing is a poor-quality mp3 and hits those high-end pitches that almost seem to pierce your ears.

I've re-run audessy since adding the amp but didn't notice and improvement.

Any thoughts or suggestions?

Thanks!!