Help! New Nagaoka MP 500 Cart Makes Hum Ground Noise

The hum is in both channels but much more louder in the right channel. Happens with the turntable power is off (but plugged in)

You need to have subwoofer and turntable plugged into the same circuit otherwise you’re grounding your table to your subwoofer if sub is connected on another circuit and that creates a ground loop. Or disconnect sub ground wire from phono stage. Why do you even ground the sub?

Thanks @audphile1 but it did not help. Good idea, though. 

Update: It has to do with the RCA cables that came with it. I found, with the volume high, if I tap the cables with my fingers I can hear the tap in the speakers!

What do ya'll make of that? These are brand new that came with the turntable! 

If the hum is audible above normal listening levels don’t sweat it. In all honesty what expectations can you have from a built in phono in your integrated? It will perform differently with different cartridges. Some will match better than others.

Also, if you have any network components close to your phono stage or cartridge you will subject it to RFI. Routers, wifi extenders, streamers should should be at least 1-1.5m away from phono stsge or cartridge. If turntable is close to amplifier the power transformer in the amp may also cause interference. Move it away.