6V6's vs. 5881's

Discussion in 'Amps and Cabs' started by terrapin, Sep 17, 2010.

  1. terrapin

    terrapin Supporting Member

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    I have an amp that will take several different power tubes. I am presently running 6V6's and they sound great. I was wondering what difference I might realize if I changed to 5881's. I mainly play pretty clean with an occasional dose of an OD pedal.

    Any thoughts?
     
  2. voojo

    voojo Silver Supporting Member

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    A little bit tighter, slightly more headroom but they still have a nice grind. I had a Stephenson 30 Watt amp that could take different tubes (cathode biased) and I found the 5881s to be my favorites, followed by 6L6s.

    I think since you play clean you would benefit, and they overdrive nicely. They do seem to throw off a lot of heat!

    I also had a Stephenson 20 Watt amp that could take all those tubes plus it had wider tube socket spacing so it could also take KT66s. Now the KT66s were monsters! My favorite tubes by far.
     
  3. terrapin

    terrapin Supporting Member

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    My amp can also take KT66's..................
     
  4. ChazMania

    ChazMania Silver Supporting Member

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    I've recently become enamored with KT66's. I'm using them in a Morgan RCS35 and they just have something that I have not had before. More midrange and growl than 6L6.
     
  5. redtoploader

    redtoploader Member

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    Yep...kt66's are in a class by themselves. I kinda think of them as having the nice qualities of both a 6v6 and 6l6. Nice and juicy like a 6v6, but all the depth and clarity of a 6l6.
     
  6. terrapin

    terrapin Supporting Member

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    Hmmmmm!! perhaps I should go with KT66 instead of 5881?? How are the cleans as that is WAY important to me???
     
  7. itgoesto11

    itgoesto11 Member

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    Sounds like you may have a Tweaker? Is so I can chime in here. I believe that KT-66s may be too tall to fit in the head cab without removing the top grille. I switched out the stock 6v6s for Tung Sold (5881s) and love the amp this way. The 6v6's do a bit better at the Fenderish cleans but the 5881 is a nice compromise and to my ears sounds much better with some gain, especiallly with the master past 1:00.
     
  8. terrapin

    terrapin Supporting Member

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    No I have a Juke 112 combo

    [​IMG]


    [​IMG]

    As you can see from the rear shot I have PLENTY of room..........
     
  9. Schroedinger

    Schroedinger Supporting Member

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    I believe that a 6V6 is a lower powered tube than a 5881. And I don't get these amps that say you can just change tube types at will, because they all have different bias requirements. If you switch from 6V6's to 5881's, you'll probably hear a difference- but it won't be the tubes you're hearing, it will be the fact that the bias isn't correct for one or the other. It probably won't hurt the amp if your transformers are big enough, but it may sound kinda bad.
    5881's are pretty close to 6L6's. KT66's are very close to EL34's. And all of those tubes are biased pretty similarly, so you can change them pretty freely without big bias changes. You can sub any of these or a 6V6 and it will work fine, but will probably break up very early because they will be biased way cold. If you have the amp biased for 6L6's or EL34's and you plug in 6V6's, you'll probably burn up the tubes, then the power transformer.
     
  10. Schroedinger

    Schroedinger Supporting Member

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    Again- you should actually have a lot more clean headroom with the 5881's. They are probably biased very cold, and are breaking up very early. That's not necessarily bad- sounds like you like the sound. Just be aware that you can probably get more clean volume with a bias adjustment.
     
  11. redtoploader

    redtoploader Member

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    Kt66's are actually part of the 6l6GC family. Where they are similar to el34's is filament current draw.

    They will draw more than a regular 6l6 so be careful about putting them in an amp that cant take the current. If Juke says the amp can take it, you could always give it a shot.
     
  12. redtoploader

    redtoploader Member

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    And agreed about the bias...some of these amps can take the tubes without damage, but it's usually a compromise- some biased to cold, bit too hot, etc
     
  13. voojo

    voojo Silver Supporting Member

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    To me, in my amp, the KT66s actually had the most headroom, and sounded big. I loved the clean tone, slightly less scooped sounding than a 6L6. When they do overdrive it's a nice big roar, but not harsh at all, and not too compressed either (both qualities I hate, compression and overly bright.)

    I think I would really give the KT66s a whirl, but be warned I don't think that some KT66s will work with those beartrap style tube retainers - which I think can be removed fairly easily. Some KT66s, including the Gold Lion reissues that I have have a tapered base.
     
  14. terrapin

    terrapin Supporting Member

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    So the Gold Lion reissues will work with the retainers???

    Thanks,
    Russ
     
  15. voojo

    voojo Silver Supporting Member

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    Actually I was told they wouldn't fit, but I can't say that with certainty. My amp was a head that held the tubes upright so I just had the builder leave them off. Since they are tapered maybe the retainers would squeeze them out?
     
  16. hawkeyeinexile

    hawkeyeinexile Silver Supporting Member

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    my Juke 1210 has EL34s, my "RedHead" (same circuit) KT66s, and my 112 had 6L6s (same circuit, etc., was originally 5881s). Gary Croteau (Juke Amps) has an option for switching tube types between 6V6 & 6L6-family tubes, but i'm *guessing* that requires different transformers than you might have.

    so, best answer: call Gary & ask him.

    re 5881s: i prefer those over just about anything, but that's personal perception (everybody's is different, there's no empirical test). they'll handle/put out twice as much power (or more), giving you more headroom. the cleans are very clear & lows are tight or well-defined, overdriven they're smooth. with a Juke the highs can be nice & chimey, too, depending on guitar, etc....

    :cool:
     

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