Pics will be posted as soon as i'm under way.
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
Bob Latino wrote:If you install the SDS board into an ST-70 with the VTA driver board I would use the bias system on the VTA driver board. The bias system on the SDS board is set up for TWO bias pots while the VTA driver board has FOUR bias pots. To answer your questions.
1. The RED/BLACK wire from the power transformer is the bias winding. Connect this directly to the "-50 VAC" eyelet on the back edge of the VTA driver board.
2. The GREEN/YELLOW and the BROWN/YELLOW wires from the power transformer are the 2 X filament center taps. These two wires will now connect to the two "FCT" eyelets on the SDS cap board.