Is an isolated powered (f.e. by battery) 5V DAC outputting RCA equally performing to a non-isolated DAC outputting XLR?

[Punchy_Power_Cat]

Basically: Does a RCA plug behave like a XLR plug SINAD-wise if there is no ground loop in the system outputting the RCA?

Would the following chart be correct?

e3 Audio A5 amp as tested by amir fed from:
XLR(switching powered DAC): SINAD about 105db
RCA(switching powered DAC): SINAD about 101db
RCA(isolated powered DAC): about 105db (?)

 

[Philbo King]

The battery one should/could be better. No possibility of ground loops. It depends on the strength and type of RF interference sources in that location at that moment.

 

[kemmler3D]

No, not necessarily. XLR reduces noise vs. RCA by passing an extra copy of the signal that's used to remove noise by comparing them.

Battery power would reduce noise that comes from the power supply, or ground loops, but in the case of this amp it's already doing a great job of that via other means.

 

[unpluggged]

XLR (or, more specifically, balanced) connection is not about ground loops. It's about interference reduction using cheap cabling (where coaxial transmission lines are overkill or too cumbersome to use). When using balanced interconnects, grounding should be as good as in the case of single-ended ones. While one can relatively easily break a ground loop by lifting the ground in a balanced interconnection, it's still not an optimal (and often not a safe) measure.