I like parafeed output circuits, they seem to swamp the loudspeaker resonance so they are much more tolerant of load. I guess there is probably some trick about setting the Q of the parafeed cap and transformer to keep it from getting tubby, but that's probably in the sizing of the components. I don't know, I just know I like what I've heard.

I guess the Radio Shack 70V transformer work pretty well, and the price is right too. That's cool. Since you're using a common distribution transformer, can you get substitute parts from other companies too?