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 products and all products

    The Dan Steele ST-70 II amp rebuild

    Bob Latino

    Posts : 2644
    Join date : 2008-11-26
    Location : Massachusetts

    The Dan Steele ST-70 II amp rebuild

    Post by Bob Latino on Wed Apr 03, 2013 11:58 am

    In the mid 1990's California tube tech Dan Steele was rebuilding Dynaco ST-70's with an interesting look. The amp had no driver board - everything was hard wired into the circuit. The circuit used a combination of Dynaco, Scott and Williamson circuits. This amp used an EF86 voltage amplifier and a 6J5 phase splitter/inverter. He also added more capacitance to bring the DC storage from 90 uF to 290 uF. The amp had a front switch, a bias meter and two "eye" tubes that indicated output level for each channel. Photos below ...

    A larger view of Dan's schematic seen below may be found here > Dan Steele ST-70 schematic



    Posts : 151
    Join date : 2011-05-09
    Age : 50
    Location : Texas

    Re: The Dan Steele ST-70 II amp rebuild

    Post by denny9167 on Wed Apr 03, 2013 8:05 pm

    Who needs to spend loads of money for AR gear,when you have cool amps like that out there!!!

    Posts : 1463
    Join date : 2008-11-30

    Re: The Dan Steele ST-70 II amp rebuild

    Post by tubes4hifi on Wed Apr 03, 2013 9:10 pm

    I'll bet that rectifier tube didn't last very long with 100uF attached to it !!! pale

    Sponsored content

    Re: The Dan Steele ST-70 II amp rebuild

    Post by Sponsored content

      Current date/time is Wed Jun 20, 2018 3:35 am