The Dynaco Tube Audio Forum

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The Dynaco Tube Audio Forum

Dedicated to the restoration and preservation of all original Dynaco tube audio equipment - Customer support for Tubes4hifi VTA tube amp and preamp kits and all Dynakitparts.com products


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    variety of 6l6 tubes

    Tubes4ever
    Tubes4ever


    Posts : 167
    Join date : 2015-07-14
    Location : Star, Idaho

    variety of 6l6 tubes - Page 2 Empty Re: variety of 6l6 tubes

    Post by Tubes4ever Wed Jul 15, 2015 9:52 pm

    Adding to this thread.....6L6 metal tubes and 6L6G, GA and GB all have a maximum screen voltage of 270V to 300V, depends on what data sheet you are reading. Max plate is 400V
    The ST70 has a screen voltage that is over 400V.  I tried original 6L6s in my ST70.  I had to turn the bias pots much more counterclockwise to get the 6L6s down to 40mA than with EL34s.  I measured the bias at -37V.  The 6L6 data says that at 300V on the screen and 400V on the plate, the bias should be around -25V.  I think the tube simply isn't designed to have such a high voltage on the screen.

    Bottom line is that only 6L6GC tubes are designed to have 400+ volts on the screen.

    Tim


    Last edited by Tubes4ever on Wed Jul 15, 2015 9:58 pm; edited 1 time in total (Reason for editing : additional information)

      Current date/time is Fri Mar 29, 2024 3:52 am