Hum in speakers

Hello all

I am trying to set up a modest audio system and cant figure out why there is a hum when I turn the volume up past 55. It only happens when there is vinyl spinning. If I turn volume up without vinyl on there is no hum. Below 55 volume the hum is not there.

note: I did set the speaker impendence to 6 ohm via the receiver settings. 

Set up is:

 - Sony STRDH190 2-ch stereo Receiver

 - Warfedale Denton 80 Speakers (16 g speaker wire)

- Technics SL-1500C Turntable 





I think most, but not all,  rca cables are adequately shielded for use with a turntable.

I was more thinking you could "borrow" a set you already have from another component. 

You haven't routed your RCA from TT to phono stage near a transformer or other power source have you? That will create hum everytime (almost anyway).