I have a PH2 from Audio Research. It is completely balanced from input to output. A quick look at the schematic and it's easy to tell. The ground runs right down the middle of pin 2 and pin 3. I can't say from experience yet that it sounds better than single ended because I'm running mine into a single ended line stage, but theoretically noise picked up from cartridge output pins throughout a balanced chain will be common mode rejected giving you a lower noise floor and less interference/interaction from outside sources. Good idea given the lower output of phono cartridges
