Looking for an integrated amp around 4000 to 5000.

Unison Research?

@pal As @klh007 asked, what can you tell us about the sonics you’re seeking in an upgrade that you’re not getting from your amp? I can’t believe (well yes I can) people are just recommending gear left and right without even understanding your musical priorities. People will always just recommend their favorite brands or what they use themselves without listening to you or asking probing questions.

Can you describe the "change" you’re looking for? If you are simply looking for a change then that’s easy - just buying something else....anything else.

And why do you need a line out for a sub?  Many people find it sounds best to simply connect to a high level input on a sub.

Seconds on Parasound gives you everything that you need and John Curl designed.

If you are going to go tubes, Line Magnetic 805ia over the PL Evo 400 any day. It’s in a different league and within your budget. Every single person who’s actually listened to both will say so. As an example, someone above said that Spendors D7’s with the PL sounded sloppy and boomy, whereas many people pair the LM and Spendors with excellent results. It’s really an amazing amp.

+1 to Line Magnetic LM-508IA or LM-805IA.
Its on another league for me too and for a guy I know that have tried many Line Magnetic amps an another brands, those models are the best. 
I've tried my LM-508IA vs a well regarded class D amp that I also own and the LM-508IA is better. You wont regret it. Its a beast.