At least a few times per week we get asked to diagnose diamond noise, so we thought we'd go through some diamond styli that have been sent in for resharpening and make a blog post to help out those learning. Below is a few examples of damaged diamonds, along with one that is very worn, and the hiss that will start to come as it wears through use. You need to pay attention to this 'worn' example as it can creep in quietly and is easily masked. These are all recorded at the same volume for reference.
Diamond Broken 1
Diamond Broken 2
Left Side Damaged
Worn
Below is examples with audio using the same diamonds as a reference, along with a cut using a new ST120 diamond styli in a 362 adapter as a gauge for the noise floor, this is on the MC-02 lathe and using stylus heat.