Balanced XLR output to unbalanced TS input

[il_mix]

Hi, everyone!

Not a stompbox related question, but I know that here I can find the correct answer for my needs (and some tech info for my personal satisfaction).
I said "for my needs" since there are several XLR to TS diagrams, but I still haven't understand what's the right one I need to follow. So here I am.

SCENARIO
I have a Behringer XR18 with XLR AUX outputs. I need to connect this output to a Rolls PM351 line in (mono jack) for in-ear monitoring. I want to prepare a custom XLR to TS jack cable.

HOW TO AND CONCERNS
At first I was like "easy peasy!". XLR have a ground pin and 2 pins with the actual signals. My idea was simply to connect the XLR ground to TS sleeve and one of the two XLR signals to TS tip; now I get my unbalanced signal for my personal monitor.
Why this must work? (in my opinion, of course) The idea behind the balanced signal (pseudo-tech "explaination" here) is to duplicate the output signal on two wires, so that the same noise will be picked up on both wires along the cable, and then the noise will be removed by "differentiating" the two signals on the input. So by connecting the ground and one signal I'm simply "unbalancing" the balanced signal. Am I oversimplifying?
Then I've checked several web fonts (even some threads here). Many suggest to connect everything like I did, but also short XLR gournd to the unused XLR pin. This is said to prevent "ground loops". But this way I'm forcing an OUTPUT signal to ground... no good! Maybe this approach is to be used when TS is connected to an output and XLR to an input? Or am I missing something?

HOW TO, REALLY?
So the question is; how do I wire my cable to connect an XLR output to a jack TS input, without harming any side (in/out) and preventing "ground loops" (can this actually be a thing in my configuration?) or other unwanted effects?
I know I can buy/build an active balanced-to-unbalanced box, but I prefer to keep things simple. Signal will travel a couple of meters on stage, so no need to worry about picikng up too much noise on the unbalanced cable.

NOTE
I didn't check yet about impedance and signal level compatibility between the two devices. These are important things, but I think I won't have problems checking them by myself. And I suppose/hope there won't be incompatibility here (it's quite a common scenario to connect a mixer aux to a headphone amplifier).

[PRR]

> also short XLR gournd to the unused XLR pin

In modern times, this is usually wrong.

In ancient days, balanced signals came from transformers. If you only connect one end of the winding, you only get thin squeaks of leakage. You must bond the other side of the winding.

As you imply, most balanced outputs today are really two amplifiers, and you don't short the unused one.

There *are* magic internal connections where you can short one side and it does A Right Thing. But you can't know by looking.

And there are also "balanced outputs" with one amplifier and one dummy resistor. This can often help when feeding a differential ("balanced") input. But if you take the wrong side, you get nothing (the hiss of a 51 Ohm resistor).

Alligator clip-leads ARE your friends here.

[il_mix]

> Alligator clip-leads ARE your friends here.

So, just try the best solution.
I'll do it.

I got your explaination for "old style balancing". But about nowadays ones, so op-amp outputs, isn't it actually bad to ground an output signal? Will it harm the op-amp?

[il_mix]

Here Iam!
I've finally tested the cable with the mixer. As said, I've connected the ground (XLR pin 1) to the TS sleeve, and just one XLR signal (in my case XLR pin 3) to TS tip; other XLR signal is floating.
The signal arrives to my headphone amp without any weird noise. So this connection is OK!

On the other side, my bandmate bought a Neutrik XLR-TS adapter. I've checked with my multimeter and noticed it has the second signal connected to ground instead of having it floating. No weird noises on his side, too.
At first glance, looks like both wiring are good.
But I'm still skeptical...

Again, what's your opinion about grounding an output signal? Any risk of damaging the output op-amp on the long run? Any problem in "dirtying" the ground with ad actual signal?