Nothing was visibly apparent, but I resoldered both caps at anode and cathode.

Sounds just like new. 

Thanks again guys.

Thanks Enzo and Jack. 

I pulled the chassis Saturday and did not see any physical defects but that does not mean that they are not there;  I know it wouldn't take much of a crack to cause a problem so I'm going to try the re-solder tonight. 

The silicone fix for stabilization may have to wait for material on hand but thanks for the tip it looks like a good idea.

I'll re-post and let you know what happened.

-Billy Joe

It's probably been discussed before, but I can't find anything specific through the searches.

I've got a '98 Princeton Chorus; and it buzzes.  Sounds about like 60 Hz.  Don't have a scope.  Buzz is independent of input.  Buzz does not change with changing position of any pot or channel. 

Sometimes buzz goes away temporarily with application of a little mechanical shock.  But, only temporarily.  It always comes back, so --

filter caps or ground loose somewhere?

I do have a good DVM.

Everything I've ever heard about these amps is that they should last forever if they're treated right, but this one has been hauled around to open jams on a regular weekly basis for the better part of ten years. 

I've got experience in the electronic/electrical field, so I don't think this is just a disposable chunk of gear.  If I could get pointed in the right direction I think I could fix this.

Then if I do get it fixed, I'm going to search again and look up the thread where someone was talking about upgrading by putting in some higher efficiency speakers and adding that preamp stage.

Thanks in advance for any help!

-Billy Joe in Kansas City