Posted by Damir [ 213.202.86.221 ] on July 20, 2005 at 06:41:15:
In Reply to: Zout posted by manualblock on July 19, 2005 at 17:14:21:
See my two messages on "Group Build" forum, about 300B output stage. Damping factor and Zout are in Part 2, "chapter" 11.
Theoretical Zout is rp (internal anode resistance of our output tube), "reffered" at the secondary side, or Zout=rp/(Ra/Rsec), or in this 3k:8 Ohms example - Zout=650/(3000/8)=1,73 Ohms, giving theoretical damping factor of DF=Rsec/Zout = 8/1,73=4,6.
But, we have some winding resistances, etc...