FerdinandII wrote:
Sounds feasible. You would have to resistively load the secondary, and could experiment with higher loadings that way.
You would probably want to run the driver in class A, so why not do a constant current source.
Or, as you mentioned before I think, you would do the phase splitting in an earlier stage? In that case you don't need to make the driver into a long-tailed pair.
True, I don't need a long-tailed pair, but I'd need to ensure that the current is balanced. That's easy enough. But do I really need to terminate the secondaries? After all, it's really inductance I'm looking for not impedance. I could just as easily use a center-tapped choke. Or am I wrong?
A current source on the cathodes would be a good idea!
...now I've fetched my British GE book and see that for a high-powered AB DA100 amp they use a CT inductor (100-200H) on a pair of common-cathode, triode-wired EL84s to get 200+200V.
ETA: Whoops, those are used in *pentode* mode, and the plate resistors (47K) are shunted by a CT inductor to achieve higher voltage output. Interesting...