[Bill Kinghorn]

Something to consider re single-ended output stages, in addition to having less than half the output of the same tubes in push-pull, is the fact that a good output transformer for them is bigger and more expensive and so they're usually skimpy. They must be gapped to prevent saturation due to the unbalanced dc current, so they need more turns for a given inductance. Unless big, they usually have higher resistance loses and bad low-frequency response. The hi-fi nuts trying to build 200 Watt, "single ended, class A" audio amps using an old transmitting triode are, as I say, nuts.