Super Reverb Vibrato doesn't work

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by renfra, Aug 8, 2006.


  1. renfra

    renfra Member

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    In my '63 Super Reverb vibrato syddenly stop working.
    Can anyone help me?
     
  2. brad347

    brad347 Member

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    even if you can see the roach flashing, it might need to be replaced. The LDR usually wears out way before the neon bulb. I've replaced two of these in my amps. They seem to have a lifespan of about 40 years.
     
  3. renfra

    renfra Member

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    Thanks, but what kind of roach is suitable for my vintage
    amp?
     
  4. Swarty

    Swarty Member

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    Try the tube before you open up the amp. It is the 5th tube from the right when viewing the amp from the back (12AX7).
     
  5. brad347

    brad347 Member

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    check with the parts suppliers (hoffmanamps.com, mojomusicalsupply.com, etc) as they usually have these, or at least used to, if you determine that is the problem. Check the tube definitely first but I assumed you already did that.
     
  6. seanman10

    seanman10 Member

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    I have replaced the tube and the roach (Optoisolator). Still no Vibrato.
    Signal runs through the curcuit even when Vibrato is switched on.
    Any other ideas?
    Thanks so much.
     
  7. slider313

    slider313 Silver Supporting Member

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    There are three ceramic disc caps in the vibrato section; a .02 and two .01's.
    Replace them.
     
  8. seanman10

    seanman10 Member

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    I replaced both .01's and the .02 ceramic caps and still did not happen. But, Now I can hear the Vibrato want to kick in, but....no.
    There is a slight volume change when I mess with the intensity knob.
    Anthing else come to mind?
    The Optoisolator is from Mojo (silver dot toward the tubes).

    Thanks.
    Sean
     
  9. mark norwine

    mark norwine Member

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    if the cathode cap on the oscillator tube is old, that could be the problem.
     
  10. soldersucker

    soldersucker Member

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    There are a lot of wires under the board in that section of the curcuit.Check them(blue,yellow, brown,white)for continutity one may not be making contact.
     
  11. steadygarcia

    steadygarcia Member

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    I finally hooked up a reverb/vibrato swicth to my '68 Super last night (I bought it w/o a pedal and the vibrato was off) and although the vibrato works, it's not very dramatic. The vibrato on my other SF amps is much more pronounced. Would a tube change help this, or what else could it be? (Sorry, don't mean to hijack the thread, but the topic is very similar).
     
  12. Swarty

    Swarty Member

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    :agree +1
     
  13. devbro

    devbro Member

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    After going down the same path as you with my 68 super (AB763), I replaced the roach with the Tonecraft Surf Bug http://www.tonecraftamprepair.com/html/surf_bug.html
    It not only solved the problem, but gave me the thick lush tremolo I was after. Worth every penny...!
     
  14. steadygarcia

    steadygarcia Member

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    I may just have to try one of those Surfbugs out! How much was it?
     
  15. devbro

    devbro Member

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    As I recall, it was about 25 bucks
     

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