Grungy sound with clean needle

Nothing more fun than troubleshooting hi end vinyl over the internet....:^)

Do you have a spare cart? If so try it and see if grunge goes away. That would tell you something.

Otherwise, do you have a magnifying glass or mirror to inspect stylus with? Could be damaged or defective.

Of course always do your best to make sure any cart is mounted properly with proper tonearm adjustments for vertical tracking and anti-skate, otherwise all bets are off.

..oh and make sure the record you test with is in in good condition as well and you are familiar enough with it to know what it should sound like.