Keith,
why all the concern about high power with the 5A's? Ok, there are some demands down around 100Hz but most of the heavy lifting is being done by the sub's plate amp, which I hope is also rolling off the woofer just about that 100Hz. Anyway, I would be more concerned with synergy than just raw power numbers. You just may be surprised at what the "right" 50 watt/ch PP (or OTL) amp sounds like. Good luck with your search.
why all the concern about high power with the 5A's? Ok, there are some demands down around 100Hz but most of the heavy lifting is being done by the sub's plate amp, which I hope is also rolling off the woofer just about that 100Hz. Anyway, I would be more concerned with synergy than just raw power numbers. You just may be surprised at what the "right" 50 watt/ch PP (or OTL) amp sounds like. Good luck with your search.