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Retubing/biasing

Discussion in 'Amp Central Station' started by ty.vaughn777, Feb 13, 2013.

  1. ty.vaughn777

    ty.vaughn777 TDPRI Member

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    So I have recently purchased a peavey classic 30 and the tubes were removed from the amp and shipped separately for safer shipping........
    When I put them back in, do I need to do anything as far as rebiasing or anything special or can I just plug them back in and go?
    If something does need to be done, how do I go about it?
    Thanks
     
  2. rsi106

    rsi106 TDPRI Member

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    I am pretty sure that amp is cathode biased. No biasing necessary.
     
  3. telex76

    telex76 Doctor of Teleocity Ad Free Member

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    You can take the same power tubes out and put back in without having to rebias.
    That's assuming it was biased properly in the first place.
    When you change to a different set of power tubes thats when they need rebiasing.
     
  4. ty.vaughn777

    ty.vaughn777 TDPRI Member

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    Ok cool thanks guys!
     
  5. telex76

    telex76 Doctor of Teleocity Ad Free Member

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    It is fixed biased, but has no adjustment pot.
    Only way to adjust bias is to change the bias resistor. You could always mod it with an adjustment pot.
    If you always use the same brand of tubes you can probably get by without ever adjusting bias when you change them, but you may not ever know the best performance of your power tubes and it could shorten thier lifespan.
     
  6. BiggerJohn

    BiggerJohn Friend of Leo's

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    +1. fixed, non-adjustable bias.

    Not all EL84 amps are cathode biased.
     
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