Cracked open my Vibro Champ and saw this....

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by zestystrat, May 29, 2015.

  1. zestystrat

    zestystrat Member

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    So to start, I bought this amp YEARS ago - not knowing anything about Fender amps other than it was the Layla amp. In all the years I've had it I never opened it up or anything.

    Also - I'm a noob when it comes to fixing my amps. I don't solder, I don't try to take them apart....I have an excellent tech and I take my gear to him.

    But....I don't play the VC often and when I recently fired it up, my '76 VC was sounding a bit raspy and I was not loving what I was hearing. I've run this guy thru my 4ohm 2x12 for fun and it sounded great so I thought it was a speaker issue.

    A speaker change on a VC isn't that hard to do....pull the tubes, maybe the chassis, loosen the nuts and replace.

    So, I pull the tubes, loosen the nuts on the speaker....can't get it out.

    [​IMG]

    Okay I have to pull the chassis, again noob here but how hard could it be? I open her up and get her ready and it looks like the previous owner might have modded it...and I have caps the have to go.

    So any idea what this person was looking to do:

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    Also, good to know my ears aren't totally shot:
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  2. Silent Sound

    Silent Sound Member

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    It looks like he replaced that tube socket. The old one may have cracked or something. It looks like you could use a cap job though. If you're worried that it could have been modded, have the tech check it out when he/she replaces those old electrolytics.

    And yeah, that speaker's seen better days too.
     
  3. Steppin' Wolfe

    Steppin' Wolfe Member

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    +1 with Silent sound....someone tagged the wires on the power tube socket for some reason.
     
  4. zestystrat

    zestystrat Member

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    I agree the previous owner replaced it.

    My tech has it now and will go through it.

    I did replace the speaker lol.
     
  5. DaveKS

    DaveKS Member

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    Wow, nos masking tape, that's some mojo right there. :D
     
  6. zestystrat

    zestystrat Member

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    90's masking tape had WAY more mojo than mt from the 2000's
     
  7. smolder

    smolder Gold Supporting Member

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    Are those blue blob caps in the tone stack blistering or are those solder iron burns? It's rare that they would look like that. The white ones need to be replaced, and arguably the capcan.
     
  8. zestystrat

    zestystrat Member

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    I thought the same thing when I 1st opened it up but its wax. Normal per my tech.
     
  9. pdf64

    pdf64 Member

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    It's just wax I think; I've seen 70s boards before that were soaked in it, like a pickup, but in to try and keep moisture out of the board, likely in an attempt to keep the tweed disease at bay.

    Yes, likely at least some are just sat there doing nothing, ie excessive ESR.
     
  10. zenas

    zenas Member

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    The blue coupling cap used in the 70s look like that kinda buldged. Nothing to worry about at all they're dipped instead of molded like the 60s blue caps.

    I've had the same failure rate with types of both blue caps on Fenders.
    Zero and counting.
     
  11. VaughnC

    VaughnC Supporting Member

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    Having your tech replace the 100k carbon comp plate load resistors with film type might make the amp quieter if they've taken on moisture over the years.
     
  12. Baxtercat

    Baxtercat Member

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    Zero & counting... :-D

    btw, re Layla, Bobby Whitlock was there and said:
    It was very quiet in the room when we were recording...You couldn't even talk or sing along because Eric was playing through a Pignose amp and talking was louder than the amplifier...It was a tiny little thing that the inventor had brought by for Eric to check out...He brought two by and gave Eric one and gave Duane the other one...They had rubber noses..The amps did...That record was recorded with Eric playing a Pignose and a Champ amp...BW c2008
     

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