Humming sounds like a grounding problem. Is your TT grounded to the amp or pre-amp? You might try moving it around to different components.
Are all you components plugged into same outlet? If not, try that. If none of that works, then try the cheater plugs.
Dave
Are all you components plugged into same outlet? If not, try that. If none of that works, then try the cheater plugs.
Dave