My Protostar is making a way different noise than when I bot it. What happened to it?
How long have you had it for? And did you buy it brand new?
It reached puberty and it’s bearing noise “cracked”.
Just kidding. Louder or softer? Maybe some grit worked its way into the bearing. Maybe it needs a touch of lube or a cleaning.
Is performance affected?
Well he told me the Proto was still pretty new, so I’m thinking it’s probably the center trac breaking in. If not that then maybe grit as you said. Either way, it is most certainly a bearing issue.
My bearing has done the same thing, but mines ceramic, so I must have broke it in 
Frankly I don’t understand all of this concern with bearing noise changes. Most of mine change from time to time but they still spin and play the same. That is all that matters really.
Since I do audio for a living, I notice when the sound changes.
We’re dealing with a lot of new people needing to learn. They are going to be more aware of anything different, and then grow concerned. However, it can be a leading indicator that something may be going odd. However, until performance changes, I don’t worry about it.
I notice subtle changes all the time. I do agree with you. If performance isn’t affected, it doesn’t bother me. It is true, that’s all that matters.
agreed. I only worry about major noise changes.