09-03-14: Charles1dadAs you realize, Charles, there are obviously a great many design dependent variables involved. But I suppose that there is probably a loose/partial correlation between SET and greater stress on tubes, due to the fact that SET designs (or at least conventional SET designs) of necessity operate with Class A bias (thereby consuming lots of power at all times, relative to the power capability of the amp), while of course many push-pull tube designs are Class AB.
What I don't know is this, SET vs push pull circuits, is one inherently "tougher" on tubes than the other? Or is there a wide spectrum in terms of stress/demand with either topology that's the overriding factor?
Best regards,
-- Al