which turntable or how to convert to balanced phono setup?

dover

You said you've never heard it. Why do you post speculative brouhaha about something you've never heard.

That is the logical fallacy known as the excluded middle:

... the principle of excluded middle states that for every proposition, either this proposition or its negation is true ... Another Latin designation for this law is tertium non datur or "no third [possibility] is given". In classical logic, the law is a tautology.

Audio Reference phono stage you refer to is quite different to what's being discussed here. Personally, I rate them 3rd class - crass, noisy and fragile compared to top units available today.

Would you please tell us about your experience with ARC reference phono stages? I'd be happy to share mine.

Reviews suggest the RCA inputs (and outputs) on the PE505 offer the option of unbalanced operation, as I suggested might be the case. Don’t use them if you want to take advantage of the balanced circuitry.

lewm

Reviews suggest the RCA inputs (and outputs) on the PE505 offer the option of unbalanced operation, as I suggested might be the case.

Of course you're running unbalanced if you're using the RCA outputs. But it looks like it's fully balanced when using the RCA inputs and XLR out, at least according to this "review":

From the head amplifier to the equalizing amplifier sections to the buffer amplifier section on the final output stage; the PE-505 employs a fully-balanced circuit design throughout all stages ... Even unbalanced signal on the conventional RCA input is converted to the differential processing mode right after the input terminals. (Emphasis added.)