Balanced or single ended leads from your arm.

George a: thanks for the update. I know when I went from a RCA input to XLR it improved-rather marked...not subtle. Anyway...thanks and good luck all.

Raul,
FYI, I wish my situation had been as simple as a poorly shielded cable. I tried numerous well-regarded and highly shielded single-ended cables and none of them eliminated the RFI. Balanced cables fixed the problem and improved the sound immediately.
So, perhaps my situation is rare, but it certainly doesn't hurt the argument to go with balanced cables when possible.
FWIW, I agree with your other comments about needing a well-designed phono stage to take advantage of balanced. I just wish I knew what reasonably priced pieces you think sound good. We all can't always "wait until we can spend more", as I've often seen you recommend. Regards,
Spencer

Dear Spencer: When I make the reference to you I omit to write that a not very good circuit/lay-out design could give that kind of RFI problems. Of course that balanced cables help in your specific case.

+++++ " I just wish I knew what reasonably priced pieces you think sound good. " +++++

The word " reasonably " is not a stand alone one because it depends on many factors like: which kind of quality sound reproduction do you want?, what music sound reproduction priorities do you have?, which kind of trade-offs could you accept?, what importance has to you the phonolinepreamp in the analog chain? etc, etc.
There are " reasonably " priced units from: 3K to 50K ???

Btw, very good system you own, specially those Merlin's ( I really like it ) and your analog rig.

Regards and enjoy the music.
Raul.

George, I spoke with BAT today and Vladimir confirmed that because the original P10 is not balanced in the first gain stage, its does sound better and offers higher SNR using RCA inputs instead of XLR. As you mentioned, the P10SE has a fully-balanced first gain stage, and sounds better through its XLR input. It's $2K to belly up for the upgrade...