I got Some V rack and now I got Many HD3500 with this Problem
Do you have the same symptom on all presets of a target amp unit, while as a rack?
Does the symptom persist with amp as a stand alone unit?? If not, then perhaps a network issue?
Maybe preset becomes corrupt with this version firmware? Inspect, if possible, values of pertinent parameters.
Have you tried to update to latest firmware version? If so, was it recent? If so, can you downgrade to a tried and true version?
There may be a simpler reason and solution. Maybe someone else can give it a try?
I try with new firmware! and nothing, still the nosie