I have a Rega RP1 turntable, which I love and has done me well for a couple of years. Recently decided it was time to treat it to a new stylus and found that, when I put it in, the plastic holder bit would grind on the record itself as it spun. My previous stylus, despite being identical in every perceptible way, did not grind.

I thought this was a manufacturing error, popped the old stylus back on and sent off for a replacement from ortofon. The replacement has arrived and has exactly the same problem despite seeming to be identical to my old and unproblematic needle...

Thoughts? I've tried messing with the tone arm weightings but that's made no difference and I'm now out of ideas.