I recently bought an Ampeg SVT-II Pro, it is about 2 months old now I guess. Just this week I have started noticing that I actually do have a fan, before this week I never heard it running. Well now its been running, so tonight I had it on for about 3-4 hours and then turned it off. I came back about an hour later and turned it back on and all of a sudden a horrible noise came from the fan. It sounded like something was hitting it like a wire or something, so I took off the cover. When I did this it didn't make the noise right away, then after about 15 seconds it started back up. I pushed the housing just a bit and then turned it back on, it worked like a charm. Then after running for about a minute it did it again, when it happened you could see the fan slow down. It only did it for a couple seconds and stopped on its own. It then ran for another 5 minutes without a problem. I was just wondering what it could be, there doesn't appear to be anything hitting it or rubbing on it. Could one of the bearings possibly be messed up? Hopefully it won't do it again, I'm kind of leary to play because I won't be able to hear it if it does it and I'm playing. Whats the worst that could happen, burn the fan motor up? Should I get this looked at or just wait and see what happens. Like I said the amp is only a few months old and is still under plenty of warranty.