so annoying. the fact that your system is dead quiet with the CD input seems to eliminate the pre and the power as a source of the hum. so it's the TT or the phono - which are both way more sensitive than any other piece of gear. i had a TT pickup mobile phone data signals over the system if my iPhone was to close to it.
getting rid of hum is a process of elimination. so i'd double check the gain/load setting on the phono. and if you've got other equipment nearby that's not associated with music playback i'd turn all of that off to see if that resolves the problem then start plugging in one by one to double check. cable boxes are prime offenders.
getting rid of hum is a process of elimination. so i'd double check the gain/load setting on the phono. and if you've got other equipment nearby that's not associated with music playback i'd turn all of that off to see if that resolves the problem then start plugging in one by one to double check. cable boxes are prime offenders.