You guys like these voltage and bias numbers?

Discussion in 'Marshall Amps' started by Force235, Sep 21, 2019.

  1. Force235

    Force235 Well-Known Member

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    I replaced my power tubes yesterday, in my 6100 (EL34) LE. You might have seen my other post where I blew up a tube at practice, tube simply failed (Sino, less than 9 months old with medium usage).

    I ordered Phillips 6CA7s (45 bias point, 24 hr burn in), After some adjustments, I've ended up with

    472v grid voltage

    over 1 ohm resistor

    34.5mv = 16.2 watt
    30.0mv
    30.1mv
    31.7mv = 14.9watt

    Amp sounds great, do you like these numbers for these tubes and amp?
     
  2. Kinkless Tetrode

    Kinkless Tetrode Well-Known Member

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    The set seems to be well matched.

    I think the bias at about 60% is a lil cold. But if it sounds great to you that is what matters.
     
  3. South Park

    South Park Active Member

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    Check the data sheet for max bias wattage.its the bias amps you are after.70 percent of max is a good start.hope that helps
     
  4. Gutch220

    Gutch220 Well-Known Member

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    yea, 60% is fine if it sounds good to you. also try 37mV (mA) this would be 70%.
    At this point, it's all about your personal preference
     
  5. Lance Chambers

    Lance Chambers Well-Known Member

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    You can rotate the tubes through each socket and get better matching.

    That's been my experience! :cheers:
     
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  6. Force235

    Force235 Well-Known Member

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    Ahh, thanks, good comments and ideas to try.
     
  7. anitoli

    anitoli Well-Known Member

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    16w is just fine in a 6100.
     
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