so this has been kicking around for a while, decided to publish.
take my ubaltobal converter, cut it in half, and then take the top
piece, replace the input transistor with a tube...
high impedance input...
DC coupled, no negative feedback, less than .01% thd, 10db gain...
just add a high power bipolar output buffer, and cheap tube hybrid
with lots of plankton.
work in progress
http://gilmore.chem.northwestern.edu/tubehybrid.pdf
100 volt power supply real simple with TI TL783 high voltage regulator
+/-30 supplies with lm317/lm337 with boosters
cheap!