AT OC9 tracking problem. Worn out?

The highly polished diamond on the OC9 tends to wear evenly, so you probably wouldn't notice any "wear" in the sense that your car's brakes or tires might be damaged.

But, at 1000-1200 hours, the stylus is likely at the tail end of its useful lifespan and in danger of damaging your records. Replace it. I had an OC-7 and OC-9 and replaced them both around the 800 hour mark just to be safe.

Eko - Would a worn stylus account for the bad tracking? It actually still sounds very nice.

Well, because there are so many other variables, it's impossible to say whether a worn stylus is causing your problem. But, given my experience with the OC9, it's the most likely scenario. The only way to know for sure is to get it under a microscope at a knowledgeable cartridge dealer. If it bothered you enough to post this thread, I think it's worth the time to send the cartridge out for inspection just to satisfy your curiosity as to where you stand on the wear curve.

I disagree with Tfkaudio in one important respect. He may well be right that your cartridge has some life left. But cartridges are easily replaceable. Records aren't. If it were a $5000 cartridge, I might be more inclined to suggest you squeeze every drop of life from it but given how inexpensive the OC9 is, I say better safe than sorry.