What else is on the panel? If there are motors or other heavy loads,or noisy loads like lighting ballasts, I would try to put in a separate panel. Noise can be caused by voltage spikes on the line as well as grounding.
Be sure all your audio wiring is BALANCED (two wires under a shield. Connect all shields (except mike cables) at one end only to avoid loops.
John (audio engineer for 32 years)
