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    Unchained
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    12.16.17 @ 12:52 PM
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    Default 5150 iii 50 watt bias setting?

    I got some new tubes for my 5150 iii 50 watt. When I pulled the chassis out, I figured I'd check what the bias was on the stock tubes. It measured at 55! This seems really high, but I'm not exactly sure. I've read some things where folks have said these heads are biased cold from the factory. Does anyone have any solid info regarding what to bias these at?

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    Sinner's Swing! evhintexas's Avatar
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    12.09.17 @ 03:43 PM
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    Default

    pin 3 to ground is plate voltage

    25 watts dissipation / 496v plate voltage x 75% = 35 mV bias setting for each of the two 6L6 tubes.

    So I have mine set at 35 each tube right now.

    Good?

    It was at 24mV from the factory

  3. #3
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    My plate voltage measured 489v. I though 6L6 were 30 watts? I set the bias pot so the resistor measured 70 (35 per tube). I hope this is correct.

    Sent from my SM-G920T using Tapatalk

 

 

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