Do you have another cartridge you can swap in place of your Benz LP-S to see if the hum goes away? If not, you could buy an inexpensive one and try it. Obviously if the hum goes away the Benz cartridge is damaged, if the hum is still there the problem is somewhere else. Make sure your table and arm are properly grounded.
Turntable hum problem after demagnetizing
I borrowed a friend's Benz Aesthetix demagnetizer to try out. (Oracle Delphi V, Wilson Benesch ACT 0.5, Benz LP-S, Cardas Golden Cross phono cable, Pass Labs XONO phono preamp). After using it, I now have a huge hum that wasn't there before. There also is static if I clean a record with my carbon fiber brush or touch it to the stylus. Also when I touch the tonearm the hum increases. What is going on??? Any help would be appreciated.