Super Champ Power Tube Bias

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by PFunk, Feb 2, 2008.


  1. PFunk

    PFunk Member

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    I have two questions for the group, please.

    I found some RCA 6V6GTY's- they test excellent, that I want to drop into my 80's Super Champ, replacing the existing EH's which actually sound pretty good.

    1) Do these amps need/ have a bias adjustment for the output tubes? 2) Is there a device that can determine if these tubes are matched, if that would be an issue if they are not? I have no way of determining if they are.

    Thanks for any suggestions.
     
  2. Gene

    Gene Member

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    They don't have a bias adjustment pot. You should use matched tubes and measure what the bias for your RCA tubes are. Be ready to shut the amp off quickly if the bias is too hot with the RCA pair.

    You might have to change the bias voltage resistor value to accomodate your new pair of tubes.
     
  3. Bluewail

    Bluewail Silver Supporting Member

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    I had my Super Champ's Hum balance control (useless!) changed over to a bias adjust. Apparently not a very difficult job.
     
  4. PFunk

    PFunk Member

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    Thanks for the replies. I'll ask my tech if adding a bias adjustment is something that he can do. I put a third one of these GTY's that I have into my regular Champ today and there was a big difference compared to the Sovtek that was already there.

    Maybe he can determine if two of these three tubes are matched as well.
     
  5. slider313

    slider313 Silver Supporting Member

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    If you have three, bring all three to the tech to check as the one from your Champ may match one of the others. It won't matter which one goes in the Champ.
     

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