power transformer with no bias tap

[fiesta55]

I'm scratch building a 50 W Plexi from a Hoffman board and would like to use a 50W Marshall (800)replacement power transformer that I have.Problem is that it has no bias tap.Is there any way I can use this transformer?I'm using a full wave bridge rectifier .
Please keep it simple and detailed as this is my first build.
Thank you.

[bob p]

there is an existing thread devoted to this topic. try the search feature and you should find it with no problems.

[fiesta55]

Thank you for your help Bob but the search did not come up with anything relavent to this build.Could you be more specific or just help me out.Sorry if this is redundant.

[Tom Phillips]

The thread is here:
http://music-electronics-forum.com/s...ead.php?t=2545
Since you are using a bridge recto, you will need to use a capacitive voltage divider circuit ala Ampege style. There is a link in the thread to an example.
Tom

[Wicksy]

I'm scratch building a 50 W Plexi from a Hoffman board and would like to use a 50W Marshall (800)replacement power transformer that I have.Problem is that it has no bias tap.Is there any way I can use this transformer?I'm using a full wave bridge rectifier .
Please keep it simple and detailed as this is my first build.
Thank you.

Yeah, in principle you can. If the HT taps on the PT secondary are centre tapped you can build a bias circuit using one half of that winding. It'll work like the JTM 45 bias circuit.