Ty_Bower wrote:It made me think of this article I read about deriving the bias off the center tap of the full wave rectifier.
Just recently Eric Hayes send me a TAL 1773 amp of his to demo. It is a PP EL84 amp with fixed bias and 6GU7 LTP phase splitters. It really acts more like a baby Eiclone than a EL84-type amp - impressive! So, I was thinking of a mod for the ST35 to add a fixed bias source, and was considering the center tap method. My worry is that a resistor sized large enough for the bias will also have poor regulation, too, ude to the changing currents. I had forgotten about the zener center tap method. That seems reasonable to me.
For those interested, for an DIY35 mod I would probably go hybrid. Maybe get a fixed -12V bias and leave a much smaller cathode resistor in there.