Requesting recommendations for phono stage


I have a Primaluna Dialogue Premium Integrated amp with built-in phono stage.  My cartridge is a Clearaudio Maestro MM.
Can I improve significantly on the sound by getting a separate phono preamp?
Looking for recommendations.  My budget is $1,500 plus or minus.
Thanks!!
mabonn
No, he told me he was down to the last two, that was a little while ago, I figured by now he must be done. But turns out he still has a few more to build. In any case it is not that Keith Herron is done, it is just that he won't be ordering parts for another run. 

The way this stuff works, things like faceplates are one of the more expensive parts, and unlike other parts they can only be used on the one component. So he has to order a decent size production run or the costs are prohibitive. Even then it ain't cheap. That's not the only thing, just one of the bigger ones. Apparently when he looked at the costs of another run and then ran the numbers for what that would imply in terms of profits or final sales price it no longer makes sense. 

He is still around and active and building and probably will be for a while yet. Anyone wants one, there are only 425 out there, or should I say that will be out there when he is done. Big_greg yours may be P2423A or something like that. Would have to go look and see what mine is. Select group, that's for sure.
I still have parts for a couple more VTPH-2As, but I have decided not to invest in more.  - Keith Herron
@600ohms thanks for the clarification, Mr. Herron. I sent you an email earlier today. 
Keith - thanks for taking great care of me and others! The wood faceplate is lovely as you know :-)
@600