Check (clean & tighten) the ground from the arm to the phono amp. It's very likely that is the issue.
Can you ground A Rega turntable?
Have a Rega RP 3 turntable and was wondering why it doesn’t have a ground and is there any way to ground it? There are times not often but times when I go to lower the tonearm when I touch the lever I get a hum. Doesn’t happen often but it seems I need a ground. Thanks for any help.