What's the solid state amp to buy $2500?

You just missed the Herron monos that sold on Audiogon a couple of days ago for $2250, I believe it was. Maybe another pair will come along.

Go a bit higher and, if you can found one, buy a Jeff Rowland Concentra I or II.

I've had one for many years, and have had absolutely no desire to change.

also not sure what you are looking to improve upon from the Joule amps BUT I would think a used set of Herron monos would be in that price range

As noted above, the Parasound A21. It may be the best amp in that price range AND beats a lot of more expensive amps.

The Joules are a bit too lush for me these days. I'm looking for something more dynamic. Been playing guitar a lot so I'm wanting a tiny bit more of a studio sound. Just leaning over to that side some, although maybe some ATC Active Speakers are in my long term future.