Scraping sound

If you take Bill_k's advice, be careful. You have no idea how sharp that thing is. Unfortunately, I do. It will be out the other side of your finger before you even realize it went in.

I just spoke with Peter Ledermann today about my Lyra Delos which seems to be presenting the same issue as described by the OP. Not sure this helps, but Peter strongly suggested that I stop using the Delos until the ultimate cause is diagnosed. He said it could as simple as a gunk caked around the stylus to a worn out stylus. I guess my beloved Delos is going to Peter to be with its little brother -- my SS Zephyr for an inspection and a fix if necessary.

The back end has to be a bit tail up

String.... I thought the VTA for the Delos should be parallel (90 degrees) to the record.

Bif... Delos? I read this as he had a Zephyr???