plan on some trouble shooting
it sounds like a loose connection somewhere. possibly at the cartridge. unplug everything and clean all the contacts, male and female.
check the cartridge connections at the cartridge, remove and replace each one and make sure the clips are tight enough. if the clips are loose, stick a toothpick into the clip til its snug, then lightly squeeze the clip together to tighten it. the toothpick will keep you from crushing the clip and ruining it.
make sure the table is grounded to your preamp or receiver. also, make sure the suspension of the table is freely floating. anything defeating this can cause mechanical feedback called howling. it gets progressively louder so be ready to turn down the volume so you dont damage your speakers.
let me know how things go.
now go clean ALL the connections in your system.