The Stuck-Needle effect emulates what you would hear when a turntable needle can't get past a scratch or defect on a record causing one groove of the record to be continuously repeated each revolution.
How to enable the Stuck-Needle effect for a turntable:
To enable click on the turntable's button (next to FX button).
To disable either click the button, press play or stop, or select a position on the progress bar.