Ampeg V4 Transformer failure

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by radvra, Feb 17, 2006.

  1. radvra

    radvra Guest

    Not sure if this is the culprit, but after a long hibernation, I fired up my (EL-34 50 watt) modified V4 after retubing it yesterday....and after some playing I heard a loud fzzzzzzzzzz!....and then lots of white smoke coming through the output tube area near the Transformer. There are 2 open sockets from the mod, and this is where the smoke escaped.

    I opened it up and could not see any components fried, so I suspect I may have toasted the transformer. Is this typical for transformer meltdowns?

    Next question is where do ai get a replacement...and given the mod, can I go with something that is not OEM?

    Any suggestions are appreciated.

  2. AL30

    AL30 Member

    Jul 20, 2005
    Not sure what your problem is. It would be helpful if you described the mod.

    For parts - all things Ampeg

    I've dealt with them on a few occasions. Good service.

  3. radvra

    radvra Guest

    The mod was relatively simple, and has 2 EL-34's (Svetlana), a 6CG7, 6K11, and 3 12Ax7's. It also has a master volume mod.

    I pulled the transformer, and could not view any signs of damage...and the smell was awful, which tells me it may have been one of the caps burning electrolyte. The only sign of damage I can see is one of the caps has shredded it's outer shell plastic...which I originally had attributed to age, but none of the other caps has this???, so I am rethinking the tranny failure.

    Also, I screwed up because I put one of the tubes in the wrong socket, and this may have caused the meltdown. Not sure what cause and effect is on this type of mistake, but I am sure it had some impact on the failure.

    In general I was expecting some component failures based on the amp being dormant for so long...maybe 15 years.
  4. sixstringslut

    sixstringslut Member

    Dec 22, 2005
    Replace all electrolytics first before worrying about tranny. Maybe checking voltages w/ tubes removed.
  5. radvra

    radvra Guest

    Solid advice. Thanks. I was thinking of getting a cap kit from fliptops anyway, and I sent pictures of my current setup to try and optimize a kit for the amp.


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