Cornwall IV's with Accuphase E-650? good match?

McIntosh and Klipsch go great together.

I've used Luxman class A amps since a pairing with Devore 9 back in 2008 or so. That said I recently used a 550AXII with the Forte IV and wasn't crazy about the combination. A little too much control and a little bright (not how I would usually explain Luxman). I agree with the above, go with tubes with these. If you want power get a bigger tube amp.

this is good thanks

and yes I switch a fair amount, maybe not the right way to achieve things buts its been fun thus far

I didn't mean that in a negative sense, switching things up is the best way to figure out what you like and can be very fun.  Sometimes the hunt is more enjoyable then the meal.  Definitely get some experience with Accuphase, it compliments speakers like Klipsch that run slightly on the cool side of neutral, and should be easy to sell on if you don't like it.

A nice tube amp and you’ll be ecstatic.