Yes XLR to XLR if you require noise rejection.
RCA uses 2 wires, positive and ground.
XLR uses 3 wires, positive, negative and ground.
XLR will reject noise between the positive and negative points.
RCA doesn’t have the extra negative to differential bias the signals.
Its too much to type out to explain but in a nut shell that’s the basics. Google differential bias.
If if you have him on RCA make sure your amp and DAC are on the same power circuit and move RCA and power cables away from each other and use a good quality RCA shielded cable which all may help. Or try a ground loop isolator. Or use a balanced DAC.