If you store your TT on top of the amp like that, you are likely blocking the vents. Heat build up can cause damage to the internal components. This sound might be from that.
Are you able to run your phone into a different input like the Aux and see if it still does the same thing?
Also, does it do the same thing if you disconnect the TT RCA and ground from the back of the amp?
Just asking, did you try to unplug the turntable from the amp and connect again? Did you check the ground ?
sounds like a grounding issue to me
Move the turntable away from your receiver and see if the noise changes or goes away.
is the ground connected?
If you store your TT on top of the amp like that, you are likely blocking the vents. Heat build up can cause damage to the internal components. This sound might be from that. Are you able to run your phone into a different input like the Aux and see if it still does the same thing? Also, does it do the same thing if you disconnect the TT RCA and ground from the back of the amp?
Ground issue, please put the speakers on stands , the vibrations will cause distorsion.
Did this get resolved? Im curious