The Dynaco Tube Audio Forum

Would you like to react to this message? Create an account in a few clicks or log in to continue.
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


2 posters

    triode switch on st-120/bias pot location

    avatar
    pscottlowe


    Posts : 37
    Join date : 2011-09-04

    triode switch on st-120/bias pot location Empty triode switch on st-120/bias pot location

    Post by pscottlowe Tue Feb 07, 2012 8:51 am

    I have an st-120 on its way(built july 2011 with all the options) when this amp has the triode switch in the old bias pot location how do you set the bias in other words where are they located and what is the setting? my original st-70's are .156 but you know that.are there four (one for each) or two ( one for each pair)I thank you for the help, Scott
    Bob Latino
    Bob Latino
    Admin


    Posts : 3262
    Join date : 2008-11-26
    Location : Massachusetts

    triode switch on st-120/bias pot location Empty Re: triode switch on st-120/bias pot location

    Post by Bob Latino Tue Feb 07, 2012 9:13 am

    Hi,

    Switch the switches to the pentode/ultralinear mode by moving the switches toward the power transformer. The bias setting is .550 volts DC for each output tube. There is a small potentiometer near each output tube that you adjust to get the correct bias setting. Email me at Bob01605@aol.com and I can Email you the full ST-120 wired amp owners manual. The owners manual has a more detailed explanation on setting bias on the VTA amps.

    Bob

      Current date/time is Fri Apr 26, 2024 10:44 am