Advantage of Balanced over RCA for phono cables



Anticipating the arrival of an Aesthetix Io phono pre and wonder if there's solid advantage to cabling the front end with balanced cables.

The run from TTable to phono pre, and phono pre to preamp will not be longer than 1 meter. The associated gear is Aurum Acoustics solid state CD/preamp and Aurum hybrid amp (proprietary SS amp for woofer, 300B and 6SN7 tubes for mid and high frequencies).

I don't really understand the need for balanced cables for other than signal coherence and fidelity over long runs. Just my ignorance.

Hope you can help me understand the potential virtues and pitfalls.

Best, and Thanks Ahead,

David
128x128cdk84
I think you better touch base with Aesthetix. The Io has a single ended input stage and then balanced output stage. So, only a guess, is rca input cable is fine...balanced output
Kurt is correct . . . except for some very rare instances, a phono cartridge is always wired as a balanced connection - it can be thought of as a transformer with a mechanical (rather than electrical) primary. And given the ratio of a cartridge's common-mode versus differential-mode source impedance, the interconnection to the preamp can retain most of the noise-rejection performance of a balanced line even if it's terminated to an unbalanced input.

There's very little performance difference that's associated with the XLR-vs.-RCA connectors themselves as they're the same connections . . . for conventional RCAs, the separate ground wire is used in place of pin 1 on the XLR, and the tip and ring of the RCA correspond to pins 2 and 3 respectively (American standard; European standard reverses pins 2 and 3).

For the cable to the turntable, using shielded-twisted-pair construction helps preserve the impedance balance, and thus improves immunity to magnetically-induced hum. The tradeoff is higher capacitance, and for MM cartridges this can be a problem . . . so personally, I prefer simple coaxial phono cables of as short as practical for MMs, and shielded-twisted-pair for low-output MCs.

For the phono stage, so much of it is the designer's preferences for the particular topology, and whether or not it lends itself to a balanced input . . . because the balanced nature of the cartridge can make the noise rejection similar between the two. One can't escape the fact that an active balanced differential input generally a minimum of 3dB noisier than an unbalanced input, but whether this ends up being significant in the context of the entire circuit is another matter.
This is not the answer you are looking for because it's vague however in my opinion you have to try it for yourself, in your own system, to really know what you prefer. That's not an inexpensive thing to do unless you have some friends or a dealer that can loan you some balanced cables.
The signal from a phono cartridge is basically a balanced signal, so going with an all balanced system makes sense. Ralph Karsten, with Atma-Sphere, can probably explain it better than I can. (Ralph designs his preamps primarily to use balanced connections, including the phono inputs and outputs.). I suggest you contact him. He is very knowledgable and very helpful. (A true gentleman, IMHO. And this coming from a guy who doesn't even own any of his gear, although I certainly wouldn't rule it out in the future - especially his MP-1 preamp.)

FYI: I use balanced connections from my tonearm cables all the way through to my amplifiers. I am very happy with my system and have no plans to ever go back to single ended connections.
The signal in the phono cable is very low. Any rfi or hum can easily interfere with the signal. Balanced cables tend to cancel out this type of interference.
Alan