Thank you for the replies. @yogiboy , I removed the ground tab, and the hum is gone. It befuddles me that a cartridge this old would still have the ground tab, when, at least on the Shure support site, this is a known issue.
@ebm @williewonka any suggestions for a replacement TT? Under $1,000, cartridge inclusive? I assume the consensus would be to use the Marantz over the Dual.
@ebm @williewonka any suggestions for a replacement TT? Under $1,000, cartridge inclusive? I assume the consensus would be to use the Marantz over the Dual.