Hot Rod Deville burnt smell/blown fuse

[jadams]

Hey all,

At a gig last night my amp started sounding a bit off, then there was a burning smell and then the fuse blew. Today I removed all of the tubes, turned it on and there was no burning smell or blown fuse. I then put the tubes in, turned it on and no problem. Then I plugged a guitar in and played for awhile with no problems. This would be a lot easier to troubleshoot if the problem would present itself again. Any help will be greatly appreciated. Thanks.

[Chuck H]

Something is wrong because something burned. You should absolutely open it up and inspect it. Do you use the amp differently in any way at home than you do at a show? What's the difference? You could try to recreate the problem, but I would open it up instead.

Three things... Those amps are notorious for blowing filter caps. You may not notice the difference right away. If the bias supply went kaput your tubes would be running too hot and you may not notice right away. If a power tube blew the amp may still operate somewhat normally at lower volumes and you wouldn't notice right away.

I'm sure there are a host of other things that you may not notice right away. But if you smelled something burning, and a fuse blew, something inside blew up or burned up. You have to open it up. For the sake of safety if not for your own satisfaction.

[soundguruman]

I think there was a problem with the bias voltage making it all the way to the grid of the output tubes.

[Chuck H]

I think there was a problem with the bias voltage making it all the way to the grid of the output tubes.

What? Where should it be?