What's the benefit of balanced tonearm cables?

I can clearly hear the differences in balanced cable....are you saying that balanced cables sound alike?

If an RCA is used as a balanced connection, which is dicey due to the grounding scheme, the result is that it will be prone to noise pickup because of the imbalanced introduced by the connector itself.

IME using a RCA plug to terminate a balanced phono line (twisted pair with separately grounded shield) is not as problematic as you suggest. In an ideal world one would want to use XLRs. Where that isn't practical using a RCA termination won't be the end of the world. I am assuming the RCA jack connects to a "floating" transformer winding or a true diff. input.

Balanced signals have greatly reduced common mode noise, but that’s not what I would call a cable artifact, so much as atmospheric, or environmental.

What they can completely eliminate is ground loop contamination, and crosstalk.  Cross talk COULD Be caused by a non-zero ohm ground.

So three things:

• Improved common-mode noise rejection
• Eliminated ground loop
  
• Reduced L to R cross talk
  

But eliminate cable effects? That’s a bit of a stretch for me. It does not cancel out capacitance, inductance or resistance. 



Best,


Erik

This might be a little off topic.
I'd like to make a statement, and Ralph is probably the only one that can comment on it.

Let's look at the waveform coming from the cartridge. Because it is a balanced source, it looks like a pure Sine Wave. We can all envision this, because we've all seen it.

Pin 2 of the XLR carries the positive (rising) portion of the sine wave, while pin 3 carries the negative (falling) portion of the sine wave. A dual differential circuit amplifies both halves of the waveform. Eventually the positive portion pushes your driver 'out', while the negative portion pulls your driver 'in'. We get pure sound.

In an RCA connection, the center pin carries the positive portion of the waveform. Your driver moves out. But what happens to the negative portion. This is now referenced to ground. Ground can be envisioned as the center of the waveform, meaning the driver is only pulled halfway down. For all I can tell, the rest of the negative portion of the waveform is 'thrown away'. My question is: what is pulling the driver all the way back in?.

If you have a dual differential amplification chain, stay with XLR. The entire waveform will be preserved, at least until it reaches your 'unbalanced' parallel speaker crossover. 

I can clearly hear the differences in balanced cable....are you saying that balanced cables sound alike?

They will if set up correctly. You might want to take a look at the Audio Engineering Society file 48 which defines the balanced line standard. I the shield gets driven by the source you will experience cable artifact- IOW various cables will sound different, although not nearly as much as with single-ended setups.

But eliminate cable effects? That’s a bit of a stretch for me. It does not cancel out capacitance, inductance or resistance.

Its not a matter of cancellation- its a matter of reduced IMD and swamped cable artifact due to low impedance operation. In the case of a phono cartridge, the source impedance is quite low, maybe only a few ohms, often terminated at the other end by a low impedance as well. Its hard for a cable to express any artifact of capacitance or inductance in such circumstances.