5f6a build needs help

Discussion in 'Shock Brother's DIY Amps' started by fwwymore, Aug 3, 2019.

  1. fwwymore

    fwwymore TDPRI Member

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    With the MV disconnected and the presence pot reconnected:
    volume low, presence low: high pitched whistles
    volume low, presence high: sounds good
    volume mid to high presence at any setting: crackling bass notes

    Where to go from here: I could try swapping the OT primaries, I could disconnect the presence from the speaker jack.
     
  2. D'tar

    D'tar Friend of Leo's

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    Yes
     
  3. fwwymore

    fwwymore TDPRI Member

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    Epilog: There were 2 problems: 1) I had erroneously wired the extension speaker jack shunt to ground causing signal drain and 2) I wired the OT primary according to the diagram. This caused all sorts of weird problems especially with the presence control. After swapping the OT primary leads, everything started to work properly and sounding good.

    I can't thank everyone enough. Big thanks to all - fw
     
    dan40 and D'tar like this.
  4. dan40

    dan40 Tele-Afflicted

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    There is a 50/50 chance of getting the primaries wrong in any build that utilizes nfb. Always good to leave them long until the first startup so that you can verify and swap if necessary. Congratulations on getting her up and running properly!
     
    Snfoilhat likes this.
  5. tubedood

    tubedood Tele-Meister

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    Point to ponder... would swapping output trannies secondary's have been the same successful result as swapping primary's (at times they can be easier to swap).
     
  6. dan40

    dan40 Tele-Afflicted

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    If the primaries are cut to short, you can also swap the grid connections from the PI to the power tube sockets.

     
    Paul G. likes this.
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