Reverb Problem BF Vibrolux Reverb

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by tonehead, Feb 15, 2008.

  1. tonehead

    tonehead Member

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    Have a BF Fender Vibrolux Reverb. The reverb is not working and I have been troubleshooting through the logical "if ... then" possibilities. It is not the pan or the connecters, the footswitch, or the V3 or V4 tube. Having ruled out the obvious, I next am going to check for continuity on the reverb transformer. If nothing is wrong there I then will do a visual inspection of the reverb circuit to look for a charred resistor, exploded cap, broken wire, etc.

    Looking for input if you have had experience with this type of thing. I am not an amp tech, but have read quite a bit about the working of the tube amplifier and have done some minor troubleshooting/repair of my own amps. I have several Fender BFs and want to begin to service and maintain them a bit myself.
     
  2. slider313

    slider313 Silver Supporting Member

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    Have you plugged the pan into one of your other amps to be sure? If it's not the pan or a tube then it could be a bypass cap. Has the amp ever been serviced?
     
  3. mbratch

    mbratch Member

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    How did you determine that it's not the pan?
     
  4. tonehead

    tonehead Member

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    Yes, I did check the pan by plugging into one of my other Fender amps. That apparently is not the problem. Thanks.
     
  5. Vincec811

    Vincec811 Member

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    Have you tried a different set of cables? Are they plugged in correctly to the amplifier's REVERB INPUT and OUTPUT? The next thing is to put a signal into the amp and signal trace through the preamp into the reverb circuit. What aout the .02 and 500 pf coupling capacitors going into the reverb circuit?
     
  6. tonehead

    tonehead Member

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    Hey thanks for the tip. The cables are not the problem; they work when plugged into another amp and I have made sure they are in the correct place with respect to INPUT and OUTPUT. Tracing the signal into the reverb circuit and checking those coupling capacitors is a good logical next step. I should in the next few days be getting together with a friend of mine who is about two steps ahead of me in amp repair skills; we will check out what you suggested here as part of the troubleshooting process. Will let you know what we find out.
     
  7. tonehead

    tonehead Member

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    Will check out that bypass cap and let you know what we find out.
     

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