When a stylus is worn, or the suspension has begun to fail, it will not track as cleanly as before. This is first evident on more difficult to track passages, such as when a female vocalist its a not really hard or gets a bit too close to the microphone. When you start to notice this sort of change, and cleaning the stylus does not cure the problem, it is time for a replacement. It is NOT the case that slight, occasional mis-tracking from wear will ruin the record; records are not as delicate as some would make them out to be.
There is no really good way to determine the extent of wear other than listening for it. Visual inspection is nearly impossible to do right; often a visual check will not show wear or other problems that are quite evident from just listening.
There is no really good way to determine the extent of wear other than listening for it. Visual inspection is nearly impossible to do right; often a visual check will not show wear or other problems that are quite evident from just listening.