My new Music Man 410-65.

[Helmholtz]

That was another thing that always struck me about the cathode drive version, how small the crossover notch was even with such low idle current.

There is a typo in my post above.
Please replace "emitter output" with " collector output".

[loudthud]

The current drive on the Cathode allows the driver transistor to automatically force whatever Grid-Cathode Voltage is necessary for the tube to overcome the low transconductance as the tube turns on at low current. Side benefit: you don't need matched power tubes. In the typical grid drive class AB circuit, you need matched tubes and careful bias adjustment to minimize crossover distortion. The Guitar amp thing of increasing bias current to 75% dissipation actually increases crossover THD, but it also increases gain and sounds "better".