this is absolutly not normal,
there is a open loop ground on the electrical circuit, i had few yesr ago the same problem, after a long investigation, we found that it was a ground problem on my HOME ELECTRICAL CIRCUIT !!!
, so i can suggest you before blame your equipment, check your home circuit. (by deduction, plug it elsewhere on the home).

Cambridge Audio 640r,M100,VP150v3,QS8v3,EP500v3