What phono preamps are balanced

Pedrillo et al,
I am fairly certain that the Aesthetix Rhea does NOT contain a balanced phono amplification circuit. The Io does. I am also dubious about the Aqvox (read the promos carefully) and the PS Audio GCPH. (Someone will no doubt correct me if I am wrong.) All of these offer XLR inputs or outputs or both, but they are not necessarily balanced internally. As has been written here ad nauseam, if the internal circuitry is not actually balanced, there is little to be gained by using XLR connectors. I researched the Pass Xono, but I never could figure out whether it was true balanced or not.

I think I misspoke. After further investigation it seems the Aqvox is balanced for MC inputs and single-ended for MM cartridges.

BAT is balanced. I don't know who said it wasn't. AFAIK all BAT products are true balanced types.

Rhea has a single-ended phono section followed by a balanced output section. This means that you have to hook the cartridge up to the phono input in single-ended mode. In my book, this does not qualify as an all-balanced design. It may sound wonderful, and I'd like to have one, but it is not "balanced" in the sense that we are discussing. It does not even offer XLR inputs. For a lot more dough you can get the Io, which is true balanced all the way.

After reading on the PS Audio website, I certainly have to agree that they claim it is fully balanced from input to output. It is curious that they offer only RCA input jacks, no XLR inputs. This CAN work for balanced mode if the ground connection on the RCA is not in fact tied to ground but instead carries the negative phase of the audio signal. (The Hagerman Trumpet, a tubed balanced phono stage seems to do this too.) Anyway, I stand corrected pending further correction.

Most manufacturers give you just enough info to let you think what you want to think, it often seems.

Pedrillo, Most likely the 5th lead from the Graham 2.2 is just to ground the tonearm body to the preamp chassis. It's a toss-up whether you would even need to connect it. With my RS-A1 tonearm, I had hum until I ran a ground wire from the body to a screw on the chassis of my preamp. With the Triplanar, the accessory ground wire just waves in the breeze, and I have no hum. So, if you have hum, find a way to attach that wire to your phono stage chassis. I now re-read your post and see that you are using the word "pin". Sorry, but it's the same deal. I guess you are looking at the 5th pin on the DIN plug. This is the pin that is sort of at the apex of the formation of 5 pins. That too, is for grouding the tonearm body via the connecting cable. The connecting cable may or may not have a free wire that is not within the shield or terminated with a connector. That's your ground wire. Alternatively the 5th pin may be connecting internally to the shield of your balanced cable connection. The shield will convey the tonearm ground to your phono stage.