Good Suggestions for Tube Amps under 6k

Elekit TU-8600 and TU-8900 are both fantastic 300b amps; the 8600 with Lundahl transformers has strong reviews from Stereophile and elsewhere. With some patience you can pick up a completed amp on the used market, or you can tackle the build yourself if so inclined. 

This may be a little off the beaten path, (said with all due respect for suggestions of other AG family members).

I am really enjoying the addition of my new Margules ACRH - 3. 

100wpc hybrid. Powerful and musical IMO. Their site has some pretty nice offerings. 

Before dropping your Prima Luna I suggest that you try some tube rolling. For example  vintage British tubes will dramatically change the PL. 

kiwibiker

Any suggestions of the specific tubes that you might think would make a positive difference?

I know we all post about what we have used. My tube background isn't that extensive but I've had the Rogers 65v-2, I still own the LTA Z40+ integrated and now I also own the Don Sachs Valhalla. The Valhalla is about 33 watts and is really really nice. This is made now by someone Don taught to make it and has a decent warranty. If it interests you at all, I can link up the site that describes it and put you in touch with the guy who makes them now.