Modifying a bias circuit to work with no PT center tap

[pompeiisneaks]

So I took a Pro Junior and rebuilt it using Rob Robinette’s AB763 Blackvibe and upon start up I’m not getting any negative bias voltage. I am using the stock transformers of the Pro Junior there is no PT center tap.

Use Rob's fancy bias circuit, you cannot do.

Sluckey's become YODA!



~Phil

[martin manning]

But you can do bias + balance or dual bias with a capacitor coupled bias supply. This thread has shown that there are many ways to do this, and it's more complicated than most people realize!

[Yoda]

Yep, learn something new all the time!

[Yoda]

I’ve installed the new bias supply and it’s working beautifully, thanks again for all the help everyone!