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Twin Reverb help, Vibrato switch pop

Discussion in 'Glowing Bottle Tube Amp Forum' started by 100LL, Oct 2, 2020.

  1. 100LL

    100LL Tele-Meister Silver Supporter

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    I've been playing my Twin Reverb this morning and noticed that when foot-switching in the Vibrato, IF the reverb is switched in, there's a pop. Nothing crazy but I doubt it should be there (my Princeton doesn't do it).

    Interestingly, the pop doesn't happen when switching on the VIB if the REV is switched off.

    I've studied the schematic a little and I can't figure it out. Figured I would ask here given the vast knowledge and experience for this AB763 circuit.

    thanks
     

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  2. BobbyZ

    BobbyZ Doctor of Teleocity

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    Is this an old TR or a reissue? On the old ones the foot switches hook up with two RCA plugs, make sure those are tight and not dirty. Had to resolder the one with the shield on it on some, if I recall that's the reverb one. That shield is the ground for both switches.
    On the TRRI they use a 1/4 in stereo plug, haven't dealt with one of those but if that's what you got, make sure it's clean and tight too.
    Probably a bunch of other possibilities, that's all I can think of tonight.
     
  3. 100LL

    100LL Tele-Meister Silver Supporter

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    It's a '65 reissue, so the 1/4 plug for the footswitch. I tried swapping switches which didn't solve the problem. It's not too bad really, but thought I should ask because if it's abnormal I might think about some fresh caps or something.
     
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