Well, my amp collection includes a few el34 designs, dynas, SET's and a couple of PP el34's. If clean power is what you want then the Berning zh270 can put 100w into 2ohms at 2 hz. Still the best sound I get is the 45 tube driven by 801 and a parafeed preamp with HG rectifiers. Nothing wrong with PP el34's. But they're no contender for single ended done right. Actually for SE sound with big balls I lash the 10y parafeed preamp to the Berning, SET sweetness and the power of the sun. Sounds great with my wacky Fostex designs.
TC