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Yellow Jacket tube conversion???

Discussion in 'Glowing Bottle Tube Amp Forum' started by RetroTeleRod, Nov 24, 2020.

  1. RetroTeleRod

    RetroTeleRod Poster Extraordinaire

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    I’m intrigued by the Yellow Jacket tube socket converters that allow you to use EL-84s in place of 6L6s. I’m interested for several reasons. I like the idea of lowering the volume of the Hot Rod Deluxe. Also the conversion will make my amp self-biasing which appeals to me. Lastly and most importantly I love the tone of the EL-84 amps I already own; Blues Junior and a Vox AC-15. Would love to hear from anyone who has tried the Yellow Jackets. Happy Tone Hunting. Rod
     
  2. Wally

    Wally Telefied Ad Free Member

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    I’ll bump with no direct experience. I doubt that you are going to find a large difference in output volume at the same settings. There will be a difference in the onset of breakup and the characteristics thereof. I also feel that most of the sonic changes will occur due to the cathode Biasing rather than a change in the type of tube. That Blues Junior is fixed biased, has a different circuit than does the AC15, and therefor does not sound a great deal like the Vox, ime. Circuits more than power tube choice determine most of the sonic characteristics of the signal, ime.
     
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  3. bullfrogblues

    bullfrogblues Friend of Leo's

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    Quite a few years ago I found myself with a Hot Rod Deluxe and tried the same thing with the Yellow Jackets. It sounded a little different, but not really any volume change at all. Didn't last for me.
     
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  4. uriah1

    uriah1 Telefied Gold Supporter

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    I tried it and did not like the sound..but that is me.
    thought tad brighter and brittle.. imho
     
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  5. Wally

    Wally Telefied Ad Free Member

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    which would lead me to wonder what the Biasing was like for the particular EL84s in that amp because that cathode bias8ng should have gone the other way instead of getting brittle, ime, unless one had some cold EL84s. Even in cathode biased circuits the tube’s Biasing, which would be determined by the tubes used, has a definite effect on the sonics.
     
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  6. RetroTeleRod

    RetroTeleRod Poster Extraordinaire

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    Thanks for the replies.
     
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  7. Wally

    Wally Telefied Ad Free Member

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    Please get back to us with your take on the difference. And....bias numbers are meaningful even with the cathode biased amp. I
    Personally have to know how any circuit is working in order to have much of a thought on the comparisons thereof. Ommv....
     
  8. uriah1

    uriah1 Telefied Gold Supporter

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    FYI. I don’t think I did a bias since the instructions said I didn’t have to..if I recall.
     
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  9. Wally

    Wally Telefied Ad Free Member

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    Uriah,it is not that one has to. Rather, it is advantageous to know since the only way to maintain a certain sonic...once found...is to buy tubes that give the same results as the ones that made the amp work for you. Same maker, same model...that doesn’t get it done when one gets discriminating. The same plate dissipation needs to be maintained from set to set in order to attain the same operation...even with cathode/self-Biasing/you don’t have to bias circuits. One can make changes to the bias resistance to change the plate dissipation, but that is a lot of trouble when one can buy burned and matched tubes to maintain stability with respect to Biasing.
    Or....one can buy any set of tubes and wonder why the amp doesn’t quite do what it used to do...or. ‘Hey, why does this amp sound so good now???’ Biasing is elemental....even if there is no adjustment in a fixed or cathode biased circuit.
     
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