Phono stage options - balanced with XLR both input and output...

Holmz, the presence of XLR connectors does not necessarily mean that the signal is treated in balanced mode. I don’t know what’s inside your PH2, but AR is not known for balanced circuits.

There is a better chance of a balanced circuit when we see an XLR.
Certainly the odds are stacking up in our favor there.

When I see an RCA I assume that it is single ended, however I suspect that there could be 1 or 2 where the shell is isolated from the chassis and not connected chassis ground, but to a differential input… which would help with CMRR.

One needs 2 wires for a twisted pair and also for a CMRR balanced circuit.
The 3rd with is for a shell, but it is not absolutely required to be an XLR to be balanced.

it would be rare though.

Pretty sure the BAT (Balanced Audio Technology) phono stages are balanced in and out. Had a VK p 10 SE with Supercaps that was outstanding

Older unit though, and after 20 years became noisy. 

 I don't know what's inside your PH2, but AR is not known for balanced circuits.

I think what @lewm is saying is that Audio Research equipment is not AES48 compliant.

Mike

+1 Zesto Audio. Very quiet, excellent sound quality, balanced in and out.

I confess lack of knowledge about the very latest ARC preamps. If the internal circuitry is balanced in the strict sense of that term, then I must apologize for conveying the wrong idea. Certainly classic ARC units were not balanced, eg, SP10, 11, etc.

went to ph2 website. Mea culpa. It’s balanced.