Deluxe Reverb Volume Problem

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by Stones_Fan, Sep 9, 2008.

  1. Stones_Fan

    Stones_Fan Member

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    Hi all. I have a Deluxe Reverb with a Hoffman turret board installed. The amp just started to pass signal even with the volume on zero. It only does this on the vibrato channel. The volume is fairly loud at zero and as I turn it up it drops off to almost nothing between 3-4 and then increases rapidly from there. Any ideas? I've already swapped tubes and measured the pots. Thanks in advance.

    -Brian
     
  2. Tbone135

    Tbone135 Member

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    It sounds like a failing power tube to me.
     
  3. Gene

    Gene Member

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    This happened to an amp I serviced. Replaced pot, no problem.
     
  4. Tbone135

    Tbone135 Member

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    I totally misread your post somehow. Yeah, it's likely a pot.
     
  5. Stones_Fan

    Stones_Fan Member

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    Thanks Guys. I did try different output tubes with no change. I wont have another 1M audio pot until this weekend. I will post the results after the swap.
     
  6. bmcmusic

    bmcmusic Member

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    Another possible cause and solution. Before you swap out the 1M pot, try disconnecting the tone stack. Just unground it and try the volume. If the problem does not happen, the problem may be in the caps of the tone stack. I had this happen one time, replaced the post and had the same problem with a brand new one. Changed the 500pf in my tone stack and it worked perfectly.

    Good luck. Let us know how it turns out.

    Bob
     
  7. brad347

    brad347 Member

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    Just on a lark... try turning both channel volumes down completely.

    It almost sounds like it is behaving as if signal is getting into both channels, phase cancelling when it gets up to a certain point on the volume, and then getting louder again.

    If that's what's happening, it's a different problem entirely.
     

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