Zen V8-like Preamp using Tubes

[needtubes]

Would it be possible to build a preamp using a similar circuit to the Zen V8 Power JFET amp but use a tube instead of the JFET? I drew up a diagram of the proposed idea...

I would ideally like to use it to power 300-ohm headphones or as a preamp. I have a couple low voltage tubes (6GM8) that have a maximum plate voltage of 30V, which would seem to be right for this job. I am not too familar with the cascode amp concept, so I am probably missing something here. Would the MOSFET add any sort of current gain that would be useable for driving headphones?

Does this circuit look workable? I am not sure what to do yet for the resistor values that are missing... Any thoughts?

[MRupp]

Would the MOSFET add any sort of current gain that would be useable for driving headphones?

Hmmm no, you would still need an aleph current source on top, replacing the biasing resistors, look at the ZEN V9 (installement 4) and ZEN V2 articles for details.