Balanced phono stages: input to output

Myles B. Astor said:
So we have seven using balanced phono? Know there's more analog people out there? Everybody else SE?

What did anyone hear when they went SE to balanced in their setups?
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SE...have no real interest doing balanced phono cable and my phono pre does not accept balanced xlr input.
 
puroagave said:
Myles, nothing I stated above conflicts with Nick, in fact we're both saying the exact same thing. He's validating everything I said. The illustration above is indeed a twin-axial cable (balanced) not co-ax. I'm trying to convey the importance of the grounding scheme, again its exactly what Nick is saying.
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Exactly. But if your phono has a balanced in input, it's worth exploring even if you only have RCA on the arm.
 
I am very sorry for being an idiot, but I still feel things are getting mixed up. (Let me start by saying I am not stating any of the following comments are categorically fact, I am simply looking for clarity. I will say it once here instead of repeating after each claim.)

It seems like sometimes people refer to rca and unbalanced synonymously and xlr and balanced synonymously. When it comes to a phono connection, it's inherent floating ground, and it's naturally balanced signal this is not the case.

An rca with a floating ground connection is balanced. My ARC Phono is balanced and receives a balanced signal through its rca (only) inputs. It has no xlr inputs. The following quote is from ARC:

"The design is fully balanced, with an input circuit that allows its RCA inputs to operate in a balanced configuration without requiring an inverter."

Further, it is my understanding that other balanced phono pre's that use rca (only) inputs with a floating ground connection also receive balanced signals. I realize even Mr. Park at Allnic references his inputs as unbalanced (RCA) but I wonder to what extent this is a nomenclature issue where he is describing the connector type not the signal type. Taking a natural balanced signal and dropping it to unbalanced just to transmit through a cable because it's missing a wire and then converting back to balanced to run through a balanced phono sounds crazy!

So if we can agree that some balanced phonos (maybe not Allnic but certainly ARC) receive balanced signals via rca with a floating ground, an entirely separate discussion would be the one I have been trying to nail down here with Rob. Which asks the question: "Are balanced connections between the stylus and the preamp through rca inferior to the same balanced connection through xlr"?????

Any help on this subject would be greatly appreciated.
 
Paul, your above post was very lucid and makes perfect sense. My Klyne phono stage had balanced inputs and used RCA's - so i get it. I guess my bottom line is whatever interconnect w/ RCAs you use between your future table/arm and the ref 10 should be expressly terminated for your set-up paying close attention to how the shield is grounded.
 
puroagave said:
Paul, your above post was very lucid and makes perfect sense. My Klyne phono stage had balanced inputs and used RCA's - so i get it. I guess my bottom line is whatever interconnect w/ RCAs you use between your future table/arm and the ref 10 should be expressly terminated for your set-up paying close attention to how the shield is grounded.
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Ok Rob. I get that and now understand that to be your main point. I will be careful on this when I take my next steps. I appreciate your patience.
 
I have always wondered why some supposedly full balanced phonos don't offer full balanced inputs, but instead using a circuit to generate the negative phase of the signal!

As mentioned in the manual of the Aesthetix Io:
>The first section is a high gain, low noise, zero feedback single ended amplifier composed of two low-noise 12AX7 vacuum tubes. This then feeds a high gain, low noise differential amplifier (two 12AX7 vacuum tubes) which amplifies the signal and produces a complementary minus phase signal. Thus, the unit is balanced from the second amplification section through the output.<

Also the Pass Labs Xono:
>Output of the primary gain stage is also applied to an inverting unity gain stage to provide the negative polarity for the balanced output.<

Is there some fundamental difficulties (noise, RIAA equalization??) in making a full balance input in phonos?
 
thekong said:
I have always wondered why some supposedly full balanced phonos don't offer full balanced inputs, but instead using a circuit to generate the negative phase of the signal!

As mentioned in the manual of the Aesthetix Io:
>The first section is a high gain, low noise, zero feedback single ended amplifier composed of two low-noise 12AX7 vacuum tubes. This then feeds a high gain, low noise differential amplifier (two 12AX7 vacuum tubes) which amplifies the signal and produces a complementary minus phase signal. Thus, the unit is balanced from the second amplification section through the output.<

Also the Pass Labs Xono:
>Output of the primary gain stage is also applied to an inverting unity gain stage to provide the negative polarity for the balanced output.<

Is there some fundamental difficulties (noise, RIAA equalization??) in making a full balance input in phonos?
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Those aren't fully balanced phonos. Some designers simply prefer unbalanced because they prefer using the fewest components in the signal path as possible in belief it maximizes sq. It seems to be one of the more contested design parameters in amplification. Right up there with sealed versus port in speakers, belt versus dd in tables, dsd versus pcm, etc. etc.
 
Hi FlexibleAudio, I can see what you are saying, but the phonos I mentioned convert the SE signal to balanced midway in the gain path. If those designers really prefer the simpler SE gain path, why not go SE all the way ?
 
thekong said:
Hi FlexibleAudio, I can see what you are saying, but the phonos I mentioned convert the SE signal to balanced midway in the gain path. If those designers really prefer the simpler SE gain path, why not go SE all the way ?
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I take your point on the Aesthetix. I am not sure why they would do that since the second stage is a true gain stage. Maybe they feel dogmatic about staying in the unbalanced domain for the itty, bitty signals in the first gain stage???

I think Nelson's Pass is just using an inverter at parity which provides no gain and just creates a balanced signal for those who want balanced output from his unbalanced phono pre.
 
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