Plinius 9200 with Spendor s8e?

Honestly, what you have now is a killer combination, and I would think long and hard about replacing anything . . . unless the sound is just fundamentally wrong. I think the S8e's sound better with tubes, as their bass is naturally accurate (no need to turn to SS for excellent bass) and their tweeter is neutral. Plus, you will surely lose that wonderful AI air that I have only heard AI create w/Spendors.

I think you are simply getting used to Spendor's version of tonal accuracy, hence the treble being "rolled off." Remember that the frequencies at which finger cymbals and hi-hat taps reside, if too dominant in a speaker's balance, can lead to serious listener fatigue over the long haul. And more watts will not necessarily bring out the high frequencies: A tweeter's natural voice will remain intact regardless of the power applied to it. I'm sure that if you spend more time with your set-up, you will begin to really appreciate what it's doing. Good luck.