Depends whether you're using transformer based gear or not.
W/tranny based gear, use a tiny piece of wire across pins 1 & 3 and run that to the shell of the RCA. Pin 2 will go to the center tip of the RCA.
With non-tranny gear, pin 1 to the shell and pin 2 goes to the center tip of the RCA. Leave pin 3 open.
This held true on my gear using a fully balanced amp & CDP w/single ended passive. The cable with pin 3 open goes from XLR female out of CDP into RCA at pre. The cable w/wire across pins 1& 3 goes from RCA out of pre into male XLR at amp.
I originally made the cable from the CDP w/wire soldered across pins 1 & 3 but got a hum through the spkrs, so removed it & the hum went away.
Both cables are non-shielded.
Additional information courtesy of Jon Risch here
W/tranny based gear, use a tiny piece of wire across pins 1 & 3 and run that to the shell of the RCA. Pin 2 will go to the center tip of the RCA.
With non-tranny gear, pin 1 to the shell and pin 2 goes to the center tip of the RCA. Leave pin 3 open.
This held true on my gear using a fully balanced amp & CDP w/single ended passive. The cable with pin 3 open goes from XLR female out of CDP into RCA at pre. The cable w/wire across pins 1& 3 goes from RCA out of pre into male XLR at amp.
I originally made the cable from the CDP w/wire soldered across pins 1 & 3 but got a hum through the spkrs, so removed it & the hum went away.
Both cables are non-shielded.
Additional information courtesy of Jon Risch here