Fuses keep blowing

Re my mention of Radio Shack fuses, see the following thread for some interesting reading (although slow blow fuses were being dealt with in that situation):

http://forum.audiogon.com/cgi-bin/fr.pl?htech&1236817549

Regards,
-- Al

I would pull out one set of tubes left or right channel and then power up;if it does not blow remove the channel installed with the ones removed try again;if it blows there is a bad tube in that set of tubes;either test with a tube tester or try to find which one is causing the fault.
Also is your incoming ac voltage steady or is it moving up and down;this could case the current draw to change and maybe blow a fuse but most likely it is a tube.
If not a tube then a shorted cap or blown grid resistor(s)
would be my next suspects.

If all tubes works...check bias adjustment..maybe went to high after a while played.

Also if outputtubes read weak but still good to use ..adjust bias below bias maximum requirement.Just a thought.

I had a similar problem with a SS amp. It was overheating.

Installed it in a less enclosed place and that corrected the problem.

Thank for the advice guys.

"Pull all tubes and turn it on. If that works, it could be a shorted tube-most likely an output tube"

Wouldn't it be better to just pull the tubes, and have them checked out on a tube tester? At least that way, I would know which tube was the "shorted" tube.

"1)Are the new fuses from Radio Shack, by any chance? If so, try some better quality fuses.

2)Are the connections to your speakers intact? If not (if one of the connections has been inadvertently dislodged) that could account for the problem, due to what is called "inductive kickback" from the output transformer, which occurs when a tube amp is operated unloaded."

As a matter of fact, yes, as it's the only place locally that I can find the 6.3 Fast Blo fuses. Also, the last fuse was a Radio Shack fuse and it lasted well over a year.

Btw, one of the first things I checked was all the connections, and they were all tight.

"blown DC capacitor --> blown grid resistor"

Think I'll check the tubes first, and if the problem still exist then I guess I'll being make a trip up to Annapolis to let the Jolida techs "under the hood".

Very possible chain of tube events:
Shorted tube --> blown DC capacitor --> blown grid resistor.

A couple of additional thoughts, beyond the (good) possibility that it is a shorted tube, or perhaps a failing capacitor:

1)Are the new fuses from Radio Shack, by any chance? If so, try some better quality fuses.

2)Are the connections to your speakers intact? If not (if one of the connections has been inadvertently dislodged) that could account for the problem, due to what is called "inductive kickback" from the output transformer, which occurs when a tube amp is operated unloaded.

Regards,
-- Al

Pull all tubes and turn it on. If that works, it could be a shorted tube-most likely an output tube.