Balanced vs. Unbalanced Inputs


I am trying to upgrade to a differentially balanced phono stage to compliment my Pass XP-22 pre and Pass X250.8 amp so as to minimize long cable artifacts and benefit from CMR. I do understand the it is the circuitry and not the input connection that determines wether a signal is balanced or not. I am looking at both a Pass XP-27 and AR Phono 3SE as possible options. Both have RCA inputs plus a ground post only. No XLR inputs. 

As far as my understanding goes, a balanced cable must have 2 signal conductors, a hot (+) and a cold (-) PLUS a ground for EACH channel. So, I sent an email to Pass Labs as follows:  

 ".... I want to confirm that there are TWO signal conductors PLUS a ground for each channel. Specifically, on each of     the RCA inputs, do the center pins and the shields carry the hot (+) and cold (-) signals respectively while the grounding wire/grounding post becomes the tone arm/turntable chassis ground connection common to BOTH channels? "

This was the response:
     "No. RCA shield and ground lug are contiguous connections."

But on the pass website is the following:
     "In order to minimize ground loop issues Pass Labs never manufactures equipment with signal ground and chassis ground contiguous."

When I email Linn about their pseudo balanced  LP12 T cable they responded with:
     "All Linn arm cables are terminated with a 5 pin DIN connector with the center pin being arm ground, which on an LP12 is also used as the chassis ground.  This is separate from the left and right channel grounds and hots which are on the other 4 pins."

Again, there is no (+) signal to be superimposed with an inverted (-) signal separate from ground for CMR. I Do have a technical background but I am not well versed on circuit design so please forgive my ignorance. I did get some very helpful advice from a member here, however, the further I inquired with the manufacturers the more confusing it became. As of now I am wary about emailing AR for fear of even more confusion. If anyone has any advice on how to proceed I would really appreciate it. Thank you all so much.

Bruce
brskie
And than, we gonna “hear “the difference  between the 2: for me RCA is more open: good balance, beautiful placement , detailed and holographic. XLR: gives also a good balance, placement:okay, but the openness is less: “flatter” compared to RCA.  Conclusion: I only used RCA. ( my system: CEC cd-player, Auralic streamer, Metronome Technologie C6 (dac), Daniël Hertz M6L ( préamp) Wavac MD 805 m ( monoblocks) and Ilumnia Magister (speakers)
Balanced vs. Unbalanced Inputs
First off you need to ascertain if they are "real" balanced outputs or "real" balanced inputs.

As many outputs are really SE, and an opamp chucked on to it to give pseudo balanced output, in this case your better to listen to the SE not the balanced.

Same goes for inputs on many amplifiers they are SE input circuitry, and they again just chuck an opamp onto it so you can have balanced, again in this case the SE will sound better also.

Now for the tricky bit, you can only find this out if you know what your looking at, look inside at the input board section, or see circuit diagrams. Because no-way will they state this, in their literature

Cheers George
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Goodness me.  Opinions here are diametrically opposed on a question that should be straightforward.  The OP says he understands now but if that is the case then he is smarter than I am.

I had believed that running phono fully balanced brings a 6dB noise floor reduction and thus is very desirable given the very low level signals involved.  Having read the thread carefully and re-read it, I no longer clear that a phono output can even be run single ended (because of the cartridge 'floating' idea expressed in two posts).  Nor yet has any view been expressed here as to the respective SQ benefits of balanced vs single-ended operation  (Possibly premature as it has not been agreed what balanced operation is or whether it is possible).

I think I would be a great idea to ask the the great phono cartridge and phono amp designers to clear this up - hopefully they might all agree.  Question: precisely how are cartridge and turntable wired to the phono amp to obtain fully balanced operation?

Also it would be highly instructive to listen to the same system wired single-ended and then fully-balanced and to take noise measurements of each.
I cannot believe the arguments phrased here because of a lack of a simple circuit diagram and a bit of simple circuit knowledge.
If you wish to know the difference between a single ended circuit and a differential circuit, AND the relative grounding difference, you need a simple CIRCUIT DIAGRAM and knowledge about how circuits and especially SHIELDED circuits work. The word "ground" should be defined MUCH better for people who are "wire nuts," i.e., those who follow WORDS (OMG!) better than circuit diagrams. de KQ2E