Bias range for JMP style amp

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by iggs, Oct 12, 2006.

  1. iggs

    iggs Member

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    What is (in general) bias range in mA for a 50W EL34 JMP style amp?

    Thanks!
     
  2. Swarty

    Swarty Member

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    I'd say 30-45mA depending on taste and wildly fluctuating plate voltages (360-490V). They vary greatly and there is no hard fast timeline although early amps, circa '68/69 tend to be of the high voltage varieties while later '70s tend to be the lowest, but you can find high voltage examples later and low voltage examples earlier.
     
  3. iggs

    iggs Member

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    Thanks for the info, I figured it would be *somewhere* in that range ... it's not a Marshall and it's not vintage but the amp is modelled after the 1987 Ali.
     
  4. sundaypunch

    sundaypunch Member

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  5. iggs

    iggs Member

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    Yup ... BiasRite already on order! :AOK
     

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