With regard to Al's comment immediately above, you could set up the cable so that only pin 2 of the XLR at the preamp end is used. That way the inverting out would not be grounded and possibly damaged.
FWIW in the case of our preamps they are completely tolerant of pin 3 being grounded to pin 1.
FWIW in the case of our preamps they are completely tolerant of pin 3 being grounded to pin 1.

