Burnt a Resistor on my Vox AC-10 Build in the Power Section, need a seasoned eye on this. Building shenanigans may have occurred. ;-)

Dennis Perusse

Tele-Meister
Joined
May 12, 2011
Posts
253
Location
Amesbury Mass
Hello All,

Need to have a smarter soul than me take a look at this as I don't know if I am being stupid or it is something else going on. Recently, I have built a vox ac-10 and it was working nicely until a 100R plate load resistor burnt out on the El84 power tube. Now, once I get these teething issues sorted with it and my friend Daryll gets around to doing a sound recording for me I'll then do a build thread on it. I am rather stumped unless I think what I did was wrong.

If you look at my pictures, and hand drawn layout, you can see my resistor that is burnt. Plus you can also see that I have taken pin 3 on the El84 tube sockets and grounded both them to the socket plus the usual resistor/capacitor that it would idle up to. I'm thinking that that is where I went wrong but I'd rather hear from the hive mind on this as I think that this is it but am unsure.

Now I am also including the schematic plus my actual layout of the power section so people can see what I am talking about here. Was the reason why the the 100 ohm resistor burnt up due to me grounding the El84 tube sockets as well as pin three with the 130 R/ 50uf 50v cap that it is supposed to be connected to? If not then does anyone have an idea why that would have burnt up? I mean both schematically speaking and by my layout of it those resistors are only connecting up to the output transformer. Obviously I'll eventually need to do a voltage reading but, for now, I'm wondering if it is the grounding issue that is causing the problem.

Also, in future, should I put a larger resistor in place of the 100 R resistors just so that this circuit doesn't chew through El84's. I would love to hear people's thoughts on this. Any help here is greatly appreciated.

Dennis
 

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Dennis Perusse

Tele-Meister
Joined
May 12, 2011
Posts
253
Location
Amesbury Mass
Hello,

I appreciate the fast reply. I'll remove those grounds for the El84 tube sockets and replace both 100 R resistors as I am unsure if the other one is good or not until I dig my volt meter out and check it. I'll then see if the amp does the same thing or not. If it does then I'll start doing voltage readings and make sure that it isn't something else doing it although I don't believe that that is the case.

Thank you everyone who read it and special thanks to Lowerleftcoast for replying back to me. :)
 




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