Chassis rattle?

Here is a weird one.

The Blue Angel is on its shakedown cruise. So far I like it. But I have a odd noise. It is the same sort of slight rattle that you would think is a buggy preamp tube. Like sand falling in a big glass jug. It seems to be coming from the chassis. That is, tap on it and you get the sound. You can hear it while playing certain notes, it is not coming out the speakers. I had the chassis out and looked it all over and can't see anything wrong. Going to have to do it again.

Still no session with a band though, I wonder if the noise would be noticable.

Anybody see this one before?

Sounds like a dirty pot. Try turning all the knobs to see if one crackles. It would probably help to spray tuner cleaner into them, or replace any really bad ones.

Have you checked the chassis bolt? Is it there? Is it tight to the chassis?

Played with the band last night. Amp was a hit. The rattle isn't noticable in this situation, but..... I'll take it apart again, this time with some company. Another guy suggested that it was a pot too. I've never seen a rattling pot before. So back to searching for things to tighten. The circuit board is mounted on plastic studs. They just snap into the board and chassis, no screws to tighten there.