5153 50 watt head No sound after tube swap

justinl101

justinl101

New member
Hey guys. I have a 5153 50watt head that i threw a couple of e34ls in the other night which was working perfect prior to the tube swap. The tubes i thought were next to brand new, i had pulled them out of a JSX a year ago, andnthe music store said the tubes had roughly 20 hours on them. Well today i hooked it back up and there is no sound output and my power tubes don't appear to be glowing, even upon switching back to the 6l6s that were previously in it. I pulled the head out of and looked for internal fuses but i couldn't spot anything that looks like fuses I'm familiar with, and i can't seem to find the wiring diagram for the 50watt model.

Opinions? Should i just not touch anything and take it right to a tech?
 
justinl101":tlol8fx5 said:
Hey guys. I have a 5153 50watt head that i threw a couple of e34ls in the other night which was working perfect prior to the tube swap. The tubes i thought were next to brand new, i had pulled them out of a JSX a year ago, andnthe music store said the tubes had roughly 20 hours on them. Well today i hooked it back up and there is no sound output and my power tubes don't appear to be glowing, even upon switching back to the 6l6s that were previously in it. I pulled the head out of and looked for internal fuses but i couldn't spot anything that looks like fuses I'm familiar with, and i can't seem to find the wiring diagram for the 50watt model.

Opinions? Should i just not touch anything and take it right to a tech?
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I would just take it a tech. I didn't know these could take el34's unless it's the el34's model. Might have burned something man. Sorry.
 
mchn13":3gl7xg0s said:
justinl101":3gl7xg0s said:
Hey guys. I have a 5153 50watt head that i threw a couple of e34ls in the other night which was working perfect prior to the tube swap. The tubes i thought were next to brand new, i had pulled them out of a JSX a year ago, andnthe music store said the tubes had roughly 20 hours on them. Well today i hooked it back up and there is no sound output and my power tubes don't appear to be glowing, even upon switching back to the 6l6s that were previously in it. I pulled the head out of and looked for internal fuses but i couldn't spot anything that looks like fuses I'm familiar with, and i can't seem to find the wiring diagram for the 50watt model.

Opinions? Should i just not touch anything and take it right to a tech?
Click to expand...

I would just take it a tech. I didn't know these could take el34's unless it's the el34's model. Might have burned something man. Sorry.
Click to expand...

Screen grid resistor? Yeah, not smart.. I'm guessing the bias shot up hot enough to do some damage.
 
Isnt there a non replaceable fuseable link in the power trannys on these, the 34's draw more current and you might have opened up that link. They don't recommend the 34's for this reason. Good luck and hope your power tranny is a paper weight now. Is there a fuse in the IEC jack?
 
Yeah, sorry dude, but that tube swap was not a good idea.
Take it to a tech, and hope it ain't the power transformer that went.
Good luck with the amp!
 
Yes, as said, those 34's will run way hotter than 6L6 in that amp and not advised. Hope it gets sorted without big issues.

Also on the used market, all used tubes seem to have 20 hours or so they say.
 
Most amps are not switchable between EL34's and 6L6. If they are there is usually a switch indicating it on the back of the amp. Fingers crossed fo you man. Hopefully it's a cheap and simple fix.
 
You probably blew a fuse, which probably saved your tranny. Blown fuses are a good thing. I know they can be frustrating, but they are there to protect you and more expensive components in the amp. I blew a fuse on a JTM45 build I completed two days ago. I didn't see or hear it, couldn't even see the fuse filament being damaged. But it's why the amp didn't work after that. My tech figured it out. I was so worried about my trannies, but that fuse did its job.

And if you follow the 5150 amp page on Facebook, the amp's designer, Howard, has really gotten tired of repeating himself that the 6L6 amps will not take EL34s. Some folks just don't want to believe him and keep asking.
 
EL34s draw a lot more heater current, and bias in a different range as well. Unless the amp manual, or tech support says its okay do not put EL34s in an amp designed for 6L6s.
 
Rick Lee":xva06lzk said:
You probably blew a fuse, which probably saved your tranny. Blown fuses are a good thing. I know they can be frustrating, but they are there to protect you and more expensive components in the amp. I blew a fuse on a JTM45 build I completed two days ago. I didn't see or hear it, couldn't even see the fuse filament being damaged. But it's why the amp didn't work after that. My tech figured it out. I was so worried about my trannies, but that fuse did its job.

And if you follow the 5150 amp page on Facebook, the amp's designer, Howard, has really gotten tired of repeating himself that the 6L6 amps will not take EL34s. Some folks just don't want to believe him and keep asking.
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I hope you are right, but I'd bet he took more out than just a fuse.
 
I’d like to know what the end result and findings were with this if the OP doesn’t mind checking back in and giving an update.
 
OP, if you post this on the 5150 thread on TGP, the amp's designer, Howard, will see it and he will chime in. I don't know if he hangs here, but he definitely responds to these questions on that thread over there. He's the boss.
 
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