XLR Wiring Standards, Diagram & Pin-out (3 Pin Audio & 5 3 Pin XLR Wiring Standard. 3 Pin XLR connectors are standard amongst line level and mic level audio applications. The above diagram shows you the pin numbering for both Male and Female XLR connectors, from the front and the rear view. (the rear view is the end you solder from) Here are the connections on each pin: Pin 1: Shield / Ground; Pin 2 How to Wire an XLR to an RCA Connector The positive and shield of the XLR are joined together, either at the XLR end or the RCA end. The easiest way is to solder a link between pins 1 and 3 (shield and negative) of the XLR, rather than trying to solder the shield and negative wire to the sleeve contact of the RCA. This produces an unbalanced audio cable.