What's the benefit of balanced tonearm cables?

zombie thread come to eat your brains!

The reason you go with balanced line is to eliminate any cable artifact, and by that I mean that you may have noticed that some cables sound better than others. That goes away with a properly set up balanced line system.

Balanced line and single-ended (RCA connections) are inherently incompatible. If you have one then its not the other. There is no such thing as pseudo balanced- that would simply be single-ended.

Now all phono cartridges happen to be balanced sources. Anyone saying otherwise is simply misinformed. The coils of the cartridge will work fine if they are hooked up backwards- all that happens is they are out of phase. If you did that with a single-ended source like a tuner you would get a huge buzz.

You know that little ground wire connection that most tone arms have? The one that other single-ended sources don't seem to need? That is there there to deal with the fact that a balanced source has a ground connection that is independent of the signal. Without it the balanced source, run as a single-ended source, will buzz. Its easy to hook up a cartridge in the balanced mode- in most cases you don't do anything with the tone arm wiring. Its usually about the interconnect cable that goes between the arm and the preamp. To do this, the preamp really does in fact have to have a balanced input.

The advantage of doing this is that the interconnect cable at the source of the stereo will not have any effect on the sound of the system. If you used a single-ended setup, the cable would have an effect and would have to be chosen with some care.

The reason a balanced connection can have no cable artifact is the fact that the signal travels in a twisted pair within a shield (BTW this is how the signal travels in the tone arm- the arm itself being the shield).

The shield is there for shielding and does not have anything at all to do with the signal otherwise. The signal occurs in the twisted pair- the output of one is in respect to the other, rather than ground which is the shield.

In a single-ended setup, the minus output of the cartridge becomes the shield. In this way signal current is passed through the shield and is vulnerable to noise issues. Usually these manifest as intermodulations (colorations) rather than actual hiss or buzz.

(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. If you doubt me, just touch the shield connection of the RCA on the preamp and see what you hear. BTW if you hear nothing then its not being used in the balanced mode- this is why I say you either have balanced or you don't and there are no in-betweens.)

This is why a balanced line interconnect can be rather inexpensive and will easily keep up with the most expensive single-ended cable no worries. There are of course other advantages, some of which have been discussed here. There really is no advantage to running single-ended in this situation, keeping in mind we are talking about how the cable behaves and not really how the phono section behaves, although its a fact that a fully differential balanced phono section has advantages too.

Conclusions:
all cartridges are balanced.
the cable thus can be inexpensive.
the cost of the cable is part of the cost of the system.
So balanced line can actually be less expensive, quieter and less colored than a single-ended setup.
Again this is so far just about the cable and its advantages. This is not about the behavior of the preamp, although that certainly plays a role- perhaps a topic for another thread?

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.