I would choose Option 1 for both input and output.

You could use Option 2 for input, but not for the output.

Taken from https://theartofsound.net/forum/show...dio-Connectors:


If XLR connectors are to be used in an unbalanced system, they are wired as follows (in the case of an unbalanced source connected to a balanced input):

1. ground or shield
2. line
3. connect to pin 1

However owing to some ambiguity over the use of pins 2 and 3 mentioned above, some unbalanced systems have the line connected to pin 3, and pin 2 is connected to pin 1.

There is an addition difference in convention between American (NAB) and European (CCIR) usage. The American convention is to use female XLR connectors for sources, whereas in Europe, male connectors are used.

In the case of a balanced source connected to an unbalanced input, the above wiring scheme will cause one half of the output to be shorted. In many cases this will not matter because a low value resistor (typically 10 - 100 Ohm) is wired in series with the output, but this is not always the case and should not be relied upon. The best course of action is to wire the centre pin (signal) of the RCA connector to pin 2, with the outer (return and screen) wired to pin 1.Thus:

1. return and shield
2. line
3. (not connected)

A full and comprehensive discussion of the various options available, as well as best way to avoid earth loops in a system of components using a mixture of signal connectors (both balanced and unbalanced) has been carried out by Rane Sound Systems, and is described in their technical note 110: http://rane.com/note110.html.