Our lumberjacks might decide that it would be less tiring if each were responsible for only his own side of tree. Once the first had pulled the blade towards himself and then pushed it back to the center of the tree, the second who had stood idle would pull towards himself and push the blade back to the center, while the first then rested. It turns out that this approach is the least fatiguing and allows for the sawing of much thicker trunks. The problem with this approach is the jerky trading off transitions at the center position of the trunk. This is like push-pull, Class B operation: each output device handles almost exactly half of the output waveform.

portion really does not need to be sawed at all, as a tree will fall of its own weight if the outer 90% is sawed away. Each then agrees to saw only most of his side of the tree alternately with the other and to ignore the thin-trunked trees altogether. This is like push-pull, Class C operation: each output device handles only a little less than half of the output waveform.

Push-pull  Class C operation is
like two lumberjacks working alternately on less than half

Push-pull  Class B operation is
like two lumberjacks working alternately on their half

  Class C is the most efficient; Class B, the second, followed by AB and last, whether single-ended or push-pull, Class A. (Other than radio work, Class C finds little if any use in audio design.)

   Let us say that an agreement is made between our lumberjacks to avoid the jerky transition phase of the saw stroke. They agree they will saw as before but with the exception that they will saw together with equal pushing and pulling for only a few center inches of the saw's motion across the tree. This approach makes for much smoother sawing, but at the expense of not being able to saw quite as fat a tree as before. This is like push-pull, Class AB operation: each output device handles only a

Push-pull  Class AB operation is
like two lumber-jacks working alternately on more than their half

    A further naming convention adds a "1" or a "2" to the amplifier class, for example, Class A1 vs. Class A2. Here the "1" suffix means that at no time during normal operating conditions of the amplifier will its power tube's grid or grids be driven into positive voltage relative to the cathode voltage. Conversely, the "2" added

little more than half of the output waveform.
Greed might compel to our woodsmen to ignore jerkiness and realize that sawing down the most trees is the only aim, that in fact the centermost

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