The Dynaco Tube Audio Forum

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


    tube life in VTA ST70

    Share

    jim151

    Posts : 7
    Join date : 2009-12-20

    tube life in VTA ST70

    Post by jim151 on Wed Mar 24, 2010 7:26 pm

    How long will tubes last in my VTA ST70.

    Bob Latino
    Admin

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

    Re: tube life in VTA ST70

    Post by Bob Latino on Wed Mar 24, 2010 9:32 pm

    jim151 wrote:How long will tubes last in my VTA ST70.

    Jim,

    The driver tubes should last 5000 hours
    The output tubes should last 2000 - 3000 hours
    The rectifier tubes maybe 1000 - 2000 hours

    In any ST-70 the rectifier tube takes the most abuse as it looks at 360 volts AC on pins 4 and 6 and maybe 430 VDC on pins 2 and 8. It is the tube most likely to fail. It is always good to have an extra rectifier tube handy to keep the music flowing. The rectifier tubes made today are just not as durable as those made in the 1950's and 1960's in the USA, Great Britain and Germany. Of the newer GZ34 rectifier tubes (JJ, Sovtek and Ruby), I have found the Ruby to be the longest lasting.

    Bob

      Current date/time is Sun Dec 04, 2016 6:20 pm