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    e80cc in center position on st-70

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    bozo

    Posts : 3
    Join date : 2012-01-12

    e80cc in center position on st-70

    Post by bozo on Sat Jan 14, 2012 12:24 pm

    Can this tube be used in this position

    Bob Latino
    Admin

    Posts : 2411
    Join date : 2008-11-26
    Location : Massachusetts

    Re: e80cc in center position on st-70

    Post by Bob Latino on Sat Jan 14, 2012 8:15 pm

    The E80CC is about the same as a 12AU7. It would be best used in the center position of the lower gain version of the VTA ST-70 driver board. I have also used on occasion a 12AU7 in the standard gain version of the VTA driver board. Although the parameters of the standard gain VTA driver board are optimized for a 12AT7 tube, a 12AU7 will also work in the center position.

    Bob

    bozo

    Posts : 3
    Join date : 2012-01-12

    Re: e80cc in center position on st-70

    Post by bozo on Sun Jan 15, 2012 12:09 pm

    I have the 12au7 version of your st70 amp. I have several e80cc tubes that I used in another preamp without any issues. I use 3 12au7's and the amp works fine. I plugged the e80cc's into the middle position and got a crackling sound out of the right channel. It does the same thing with all 3 e80cc's I tried. Bias remains stable. Any ideas.

    danskman

    Posts : 17
    Join date : 2012-01-14
    Age : 57
    Location : Bière, Switzerland

    Re: e80cc in center position on st-70

    Post by danskman on Sat Jan 21, 2012 1:35 pm

    Mmmh... if the problem arises only on one channel, with any e80cc tubes you tried, I would check the tube socket contacts tension. The e80cc could have smaller pins than 12au7. Just my 2¢...
    Best regards,
    Danskman

    bozo

    Posts : 3
    Join date : 2012-01-12

    Re: e80cc in center position on st-70

    Post by bozo on Sat Jan 21, 2012 3:20 pm

    I will check it. I can use the e80ccs on both the outside positions without a problem its only when I insert one of them in the center.

    danskman

    Posts : 17
    Join date : 2012-01-14
    Age : 57
    Location : Bière, Switzerland

    Re: e80cc in center position on st-70

    Post by danskman on Sat Jan 21, 2012 6:22 pm

    Yes, that's why I tought about the socket, especially the middle one.

    tubes4hifi
    Admin

    Posts : 1291
    Join date : 2008-11-30

    Re: e80cc in center position on st-70

    Post by tubes4hifi on Sun Jan 22, 2012 12:06 am

    the E80CC is the same as a 6085 tube, it has about 50% more gain than a 12AU7, and more important, it uses double the filament current.

    mantha3

    Posts : 298
    Join date : 2010-11-10

    Re: e80cc in center position on st-70

    Post by mantha3 on Tue Jan 24, 2012 5:17 pm


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