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View Full Version : One tube getting REALLY hot!

adangerlg
08-20-2008, 06:24 PM
The other guitar player in my band is playing out of a fairly new Fender deluxe with 2 6L6's. When playing today we noticed it sounded noisy. Looking at the back we could see that one tube was BRIGHT orange and the other tube didn't look to be glowing at all.

Bad tubes or more serious problem?
slider313
08-20-2008, 06:31 PM
I would guess the one not glowing at all is dead or the screen resistor on that socket is burnt. Replace the set and see what you get.
adangerlg
08-20-2008, 06:40 PM
Do you know if they are self-biasing?
doublee
08-20-2008, 06:46 PM
Deluxe is meant to have 6V6's, maybe a factor?
adangerlg
08-20-2008, 06:57 PM
I know he hasn't changed the tubes since he got it new, so the 6L6's are what came with it.

So would you all suggest replacing the current tubes with 6V6's or sticking with 6L6's?
phsyconoodler
08-20-2008, 07:07 PM
'Deluxe' can mean a few models.Is it a Hot Rod Deluxe?I'm guessing it is,so it will need a pair of tubes and the bias checked.That amp is fixed bias.
adangerlg
08-20-2008, 07:15 PM
No, its a Blues Deluxe which I just found out does use 6L6s.
Structo
08-20-2008, 07:21 PM
The tube redplated.
Most probably just a bad tube.

Replace the pair, rebias if necessary and try again.
adangerlg
08-23-2008, 05:12 PM
Well I went and got new tubes but that didn't fix the problem. I guess its time to take the amp to a tech. Anyone have any idea what the real problem might be and what kind of a hit to the wallet I'm gonna take?
chaz
08-23-2008, 06:14 PM
One is still redplating? Redplating is bad news. Drawing way too much current and will kill the tube fast. It could also lead to more serious damage to the amp. Amp definitely needs to see a tech.
Trout
08-23-2008, 07:05 PM
One is still redplating? Redplating is bad news. Drawing way too much current and will kill the tube fast. It could also lead to more serious damage to the amp. Amp definitely needs to see a tech.

:agree


It could very well be as simple as a leaky coupling capacitor, or dirty socket, screen resistor, but unless you are really proficient with the proper tech skills and tools, a trip to a good known tech can save you hundreds later in most cases.
Old Tele man
08-23-2008, 07:06 PM
...red-plating COULD be caused by a "loose" connection on that power tube socket...or, a broken wire leading to that connection.
twinrider1
08-24-2008, 10:47 AM
Swap the tubes around. See it the problem follows that tube.
Structo
08-24-2008, 10:59 AM
+1 move the tube to see if it is the tube or socket.
skinpimp
08-24-2008, 11:08 AM
I had that same probelm on my marshall JVM. Pulled the chassis to see that one of the output transformer wires had be piched to the chassis when they installed it . well that arced to ground and wasted one of the tubes, blew a fuse . so i fixed the wire replaced the fuse and tubes, biased , and was good to go . I AM NOT A TECH. But I know enough about Electronics to STOP and take it to one before I screw something up . so that would be my suggestion. Especially if the amp is under warranty.
Nolatone Ampworks
08-25-2008, 06:22 AM
Swap the tubes around. See it the problem follows that tube.

I think he said he already swapped the tubes, so it's unlikely the new tube has the same problem, unless somethign else hosed it right away after installing it.

I'd say it's at least worth opening the box up and doing a visual inspection for obvious signs. You may just find your answer by taking a peek. Just don't TOUCH anything unless you are aware of the danger and comfortable with safety practices!