When to choice XLR over RCA ICs.

@atmasphere we are mostly in agreement and this debate is getting tiresome.

The two benefits lost are cable immunity and susceptibility to ground loops, since ground is referenced by the output of the device. This isn’t a matter of opinion or debate. Those two things are literally the goals of the balanced line system.

The value of a balanced system using balanced lines is not confined to those two goals. This is where you drift into circular reasoning. (As you well know, balanced systems also enjoy the benefit of CMNR, whether AES48 compliant or not.) Nor is it true that being non-compliant with AES48 inherently subjects a product to being sensitive to ground loops. Again, it is implementation, implementation, implementation.

We mostly agree, Ralph, so I’m inclined to leave the last word to you. Or, feel free to PM me.

The value of a balanced system using balanced lines is not confined to those two goals. This is where you drift into circular reasoning. (As you well know, balanced systems also enjoy the benefit of CMNR, whether AES48 compliant or not.) Nor is it true that being non-compliant with AES48 inherently subjects a product to being sensitive to ground loops.

@cleeds Yes, we covered other aspects already. I do not see how there is circular reasoning, but I do feel I've been having to repeat myself on this a bit 😁 That's circular, isn't it?

It is true that if the component does not support AES48 that it will be open to ground loops. This isn't to say that will always happen, just as with single-ended gear it doesn't always happen. But if you don't take steps to deal with the ground loop issue, it'll be a problem sooner or later. This is fact, simply because ground is being referenced by the equipment, and when ground is referenced, then noise in the ground can get amplified. That is why in balanced systems going back 70 years ground is ignored.

I don't care to debate this either since I've repeated myself so much (not all on this thread). I have been amazed at how much misinformation exists around this topic. But if you have the interest, you might take a look at this book on transformers by Bill Whitlock, of Jensen Transformers fame.

If you look at the schematics, you'll see there are no center taps- that in fact the balanced inputs and balanced outputs are always floating.

atmasphere

The balanced signal volume is a barely, but recognizable increase in volume, no way is is that much.

@atmasphere 

Thanks for the information re: jury rigging XLR/balanced connection.  I may do so.

I became interested in the topic because I have (and love) a VPI Avenger Titan turntable with a Fat Boy tone arm.  The Avenger has a separate unit where you can precisely adjust the speed of the two AC motors (that, in turn, rotate a magnetic plate).  The power cord that ran from the control unit, unfortunately, was a bit stingy and ran parallel to my Cardis phono cables for a good bit and I got a fair amount of noise.

I resolved the issue with an nice, shielded, after market power cord (nothing exotic).  Not sure if it was from the shielding or simply because I bought a longer cord that allowed me to drop it behind the console, so it did not run so close to the phono cables.  Anyway, problem resolved.

But the process did get me thinking about balanced/XLR turntables and phono preamps.

Turns out Pro-Ject has a line of balanced turn tables, using what looks like "microphone style" XLRs, such as this:

I thought about it a bit -- and my phono preamp (which I also love) is a Parasound JC3+ (I think that's the model) and it -- despite having XLR "outs" and essentially being completely separate left and right pre-amps in one box does not anticipate XLR "in", so, given I resolved the issue (to my ears, at least) did not pursue the matter further.

I have a fair amount of Mogami wire laying about, so I may see if I can improve over the Cardis interconnects.

Thanks again.

As I understand it the primary reason for using XLR cables over RCA cables is to prevent a ground loop from occurring.  This is especially true when using long runs of audio cable (25 feet or more), which is why XLR cables are standard in professional recording studios.