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    Sylvania 5881 - Can it be used in VTA-70 upgraded ST-70 (w/Original PT)

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    fedoragent

    Posts : 35
    Join date : 2013-09-14

    Sylvania 5881 - Can it be used in VTA-70 upgraded ST-70 (w/Original PT)

    Post by fedoragent on Sun Apr 03, 2016 2:28 pm

    Folks,

    I was digging in a local store and came across some Sylvania 5881s. I believe they may have also been designated as 6L6WGB. I've heard that these could be used in our VTAs and STs in place of the 6L6GC that I love so much. Has anyone used these and in general, would it be the same bias .40 as EL34/6CA7? I'm hoping that Bob chimes in on this one. He and tubes4hifi knows all when it comes to these amps.

    At any rate, HAPPY BASEBALL OPENING DAY!

    Thanks,

    FG.

    Bob Latino
    Admin

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

    Re: Sylvania 5881 - Can it be used in VTA-70 upgraded ST-70 (w/Original PT)

    Post by Bob Latino on Sun Apr 03, 2016 8:46 pm

    FG,

    You can probably use a 5881 output tube in a VTA ST-70 but a 5881 is not as "durable" and has smaller plates than a 6L6 or an EL34. I do not feel that EITHER a 5881 or a 6L6 will last as long as an EL34 in the VTA ST-70. Also > Due to its smaller plate structure, the use of a 5881 output tube will also restrict the amp's overall power level as compared to an EL34. Instead of an "ST-70" you will probably have something like an "ST-50". If you do use a 5881 output tube, I would recommend biasing the amp at .350 VDC per each as opposed to the .400 VDC bias setting recommended for an EL34.

    Bob

    fedoragent

    Posts : 35
    Join date : 2013-09-14

    Re: Sylvania 5881 - Can it be used in VTA-70 upgraded ST-70 (w/Original PT)

    Post by fedoragent on Tue Apr 05, 2016 12:42 am

    Bob Latino wrote:FG,

    You can probably use a 5881 output tube in a VTA ST-70 but a 5881 is not as "durable" and has smaller plates than a 6L6 or an EL34. I do not feel that EITHER a 5881 or a 6L6 will last as long as an EL34 in the VTA ST-70. Also > Due to its smaller plate structure, the use of a 5881 output tube will also restrict the amp's overall power level as compared to an EL34. Instead of an "ST-70" you will probably have something like an "ST-50". If you do use a 5881 output tube, I would recommend biasing the amp at .350 VDC per each as opposed to the .400 VDC bias setting recommended for an EL34.

    Bob

    Bob,

    Thanks so much! I have a 6L6GC quad that I've been using for a couple of months. They're starting to go. And I'm glad you told me that with the 5881. I won't be buying those. Smile I like the sonics of a 6L6, but I've gone back to my EL34s. I still have those KT66s that you suggested, but I keep those aside for special occasions. Thank you for the great advice!

    All my best,

    FG.

    Tubes4ever

    Posts : 61
    Join date : 2015-07-14
    Location : Star, Idaho

    Re: Sylvania 5881 - Can it be used in VTA-70 upgraded ST-70 (w/Original PT)

    Post by Tubes4ever on Tue Apr 05, 2016 12:24 pm

    fedoragent wrote:

    Bob,

    Thanks so much!  I have a 6L6GC quad that I've been using for a couple of months.  They're starting to go.  And I'm glad you told me that with the 5881.  I won't be buying those. Smile  I like the sonics of a 6L6, but I've gone back to my EL34s.  I still have those KT66s that you suggested, but I keep those aside for special occasions. Thank you for the great advice!

    All my best,

    FG.

    FG,

    I'm surprised that your 6L6GC quad are going out in only a few months.  Were they used previously?  They should last much longer than that.

    Tim

    fedoragent

    Posts : 35
    Join date : 2013-09-14

    Re: Sylvania 5881 - Can it be used in VTA-70 upgraded ST-70 (w/Original PT)

    Post by fedoragent on Tue Apr 05, 2016 4:36 pm

    Tubes4ever wrote:
    fedoragent wrote:

    Bob,

    Thanks so much!  I have a 6L6GC quad that I've been using for a couple of months.  They're starting to go.  And I'm glad you told me that with the 5881.  I won't be buying those. Smile  I like the sonics of a 6L6, but I've gone back to my EL34s.  I still have those KT66s that you suggested, but I keep those aside for special occasions. Thank you for the great advice!

    All my best,

    FG.

    FG,

    I'm surprised that your 6L6GC quad are going out in only a few months.  Were they used previously?  They should last much longer than that.

    Tim

    Tim,

    More like a year, and they were older Chinese throw away 6L6GC anyways. They were experiment Shuggies (Shuguang). They sounded great. However, one of the tubes has a rattle when it is moved and although they haven't shorted, gone white or just straight died...I am being cautious with them.

    FG.

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    Re: Sylvania 5881 - Can it be used in VTA-70 upgraded ST-70 (w/Original PT)

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