The generally accepted connection scheme for balanced to unbalanced connections is to tie pins #1 and #3 together.
This can be done at the XLR or (if you're using two-conducted shielded mic cable) at the RCA. Another connection scheme
is to connect the RCA to the XLR pins #2 and #3 only.
iFi Zen Blue V2; Century docking + KECES P8 (furutech FP-S35TC)
U DUO sp II USB cable, triple-C DC cable
Holo Audio 青 DAC (Acrolink 4020 III)
Onkyo 5010 (Neotech AE)