Technics SL Q202 turntable low buzz

I hear a low pitch buzz when I put my ear near the platter...with power on but no record playing.
The buzz is not coming through my speakers and my amp is off.
Any idea what is causing this ...or is it normal to hear this ?
Thank you
It is the power transformer. Over time the windings and laminations of the core start to vibrate because the varnish applied to them becomes brittle with age. They sometimes have rubber bushings between the transformer and plinth on those lower-end turntables, which also become petrified over time.