This has been driving me nuts for a while now. Every now and then, my JBC station would make a crackling/rattling sound. Scary, huh? Well, I've been through it, all up and down, and I could never see any obvious signs of arcing, so I just let it go. Whatever it was, it just didn't seem particularly dangerous and I figured I would track it down some day. Sometimes, you have to go with your instincts.
They proved pretty accurate this time. I'm soldering along, and the crackle come back...what the hell IS that? I look down and I see some cut leads dancing around whenever I draw a lot of power.
Turns out that if you get some magnetic leads underneath the station, whenever the thing draws more than idle power, it gives off enough of a field to drag around the leads and it makes noise.
So there you go. Can't say I've ever run into this before with any other station, but now it's solved. I'm sure someone else out there must have similar issues. I had been attributing it to some sort of squeak that I just needed to track down. I would have never guessed this!