What is that screw on my turntable used for?

AVDADDY

Grounding post if it is on the rear panel. If it is under the platter, then it is a transit screw, intended to lock the mechanism down while it is being transported.

David E

Turn tables need to be grounded to the receiver. Otherwise, you get a 60 cycle buzz. This buzz is actually 120 Hz but still rather annoying. The reason it is 120 Hz is that electronics operates using DC power. To turn AC into DC, you take the negative half of the 60 cycle sine wave and invert it getting two humps from 0 to 120 volts. This is what you hear. Grounding the Turntable to the receiver usually eliminates that.

rick29148

most better turn-tables are suspended on coil springs that isolate the turn table from vibrations, but that means they are hard to move around. they put two screws in the turn table to clamp-it-down so you can move it without damaging those coil springs ............