Feedback Issue

I am currently running a McIntosh C29 preamp along with a McIntosh MC2205 amp.  My turntable is a Technics SL1200-MK5.  I also am running an Aurender A10 as my streamer.  My speakers are old Infinity RSM that I rebuilt.  I recently acquired an audio rack and setup all the components in this rack.  After the move is when the problem started.  If I stream, I can do it all day long with no issues; however, when I switch to vinyl, I get major feedback through the system.  The feedback sometimes starts immediately, other times it will start half way through an album.  I tried both phono 1 and phono 2 RCA inputs on the C29 with the same results.

Any suggestions where to start? 


Try moving the table?  I would probably lift the ground (3 prong to 2 prong adaptor).  Tables pick up hum so easily.  

Acoustic feedback from the speakers back to the turntable. Does it stop when you reduce the volume? If so, your new rack is amplifying the sound. KAB make feet to stop that. I've not tried them but they've made a name for themselves in modding SL1200s.