engineears
... a different system with a headphone amplifier connected to a DAC with a pair of XLR cables in a balanced differential setup was getting horrendous ground hum ... I snapped both ground pins off the (removable) power cables. Hum gone instantly. (I don’t recommend this unless you know what you’re doing and what the source of your hum is ...I don’t recommend eliminating safety grounds under any circumstance - that’s treating the symptom rather than the disease. It can be useful as a diagnostic tool to isolate the source of a ground loop, but it’s not a solution to the problem.