Make sure you have a ground wire between TT/arm and preamp.
I am having trouble with "slight hum" with Pioneer PL-A45D TT
So I grabbed a pristine TT (apparently not that pristine since it hums a bit") and now I have a slight hum when the needle hits the record. With that said I have tried some trouble shooting different speakers, AMPS etc and ruled out that. I have also tried cleaning contacts. I am not one for opening it up and changing things since I dont have the knowledge to do so. Any suggestions on remedy? Thanks in advance. I know this is not a Top shelf TT however it matches a Pioneer system I put together for my collection and would like to be able to use it without the hum.