Just a historical FYI...
When talking about XLR balanced to RCA unbalanced adapters...
The idea of connecting the Signal (-) to ground comes from the old days when audio transformers were often used on audio
OUTPUTS...
And it is still true today for some balanced microphones... and for cables specifically intended to be used with microphones...
But it is not really true for most modern audio gear... including ours... and almost never for line level signals.
In the old days, if you had something like a preamp or a mixer, with a "balanced output", the output was often via an audio output transformer.
So, if you look at the schematic, the output is the secondary winding of the output transformer, with one end of that winding going to Signal (+) and the other end going to Signal (-).
Likewise, a dynamic microphone looks like a winding on a transformer, and many older microphones actually had transformers built in, so had to be treated just like transformers.
And, in order to get signal from a winding on a transformer, you need to have both ends of the winding connected.
If you connect the Signal (+) end, and
DON'T CONNECT the Signal (-) end, you don't get any output.
And, if you're connecting that output to a balanced input, then you connect Signal (+) to Signal (+) and Signal (-) to Signal (-)
And, if you're connecting it to an unbalanced input, you connect Signal (+) to Signal (+) and Signal (-) to Signal Ground.
However, with almost all modern gear, and especially line level outputs, almost nobody uses output transformers any more.
(Transformers have a few benefits, and several drawbacks, one major drawback being that good quality transformers tend to be quite expensive.)
With almost all modern gear, including ours, both the Signal (+) and Signal (-) outputs are driven (they come from the output pin of an op-amp or active line driver).
And, with this type of balanced output, there is a "real ground" on that third pin, and the Signal (+) and Signal (-) are both referenced to that ground.
And, if you do connect that Signal (-) output to ground,
you are shorting the output of the Signal (-) op-amp or line driver to ground.
Now, with most gear, including ours, this won't
hurt anything...
But you are shorting an active signal to ground... which is never the greatest idea.
(So you are "putting a bit of stress on those output drivers"... and there is certainly no benefit to be had by doing so.)
(I guess it's worth mentioning that a
very few older devices may have an output transformer with a center tap that is grounded... and they may also
NOT like that Signal (-) output pin tied to ground.)
There's also something else worth pointing out here...
When you connect a balanced output to an unbalanced input
you have an unbalanced connection...
There's nothing wrong with this... just noting that it's only a balanced connection if the output of the sending device, the input of the receiving device, and the cable between them, are
ALL balanced.
(Also note that we're talking about a
balanced connection between devices... which has
nothing specific to do with whether the devices themselves are "fully balanced" or not.)
Also, worth noting, is that it doesn't matter which end you put the adapter on...
So, for example, if you have an XMC-2 (with balanced outputs), and you're connecting it to a BasX amp (with unbalanced inputs), you will have an unbalanced connection between them.
It really doesn't matter if you put the adapter on the XMC-2, and then run a long unbalanced cable, or run a long balanced cable, and put the adapter at the other end.
And, because of this, it would be perfectly fine to use a balanced cable, perhaps one that you already had installed in the wall, and put the adapter at the far end.
(I'm always inclined to run balanced cables in-wall... since, even if you don't need a balanced connection today, it never hurts, costs almost the same, and you may want it someday.)
(Also, as someone already mentioned, if you're making your own cables, or having cables custom made, you can simply make up "one-piece balanced-to-unbalanced adapter cables".)
Not sure I would say anything is floating but your pin configuration per AES14-1992 standard currently is Pin 1 ground or shield, Pin 2 is Hot, and Pin 3 is Negative.
He wants to go from XLR to RCA. Keith told me to leave pin 3 floating as he confirmed with Ray.
1 is ground, 2 is pos and 3 is left unconnected.
