I have finished the design and testing of the CV Amp.
This uses a pair of 6CM7 TV tubes and it can output over a Watt of negative DC power into a 1k resistor in parallel with a 1uF cap. These $3 tubes are essentially half a 6CG7 plus half a 12BH7.
They operate completely in class A with the Edcor TX and are at ~70% of maximum dissipation. The feedback keeps the gain steady and brings the output resistance down to 100 ohms, the same as the Fairchild CV amp.
Best
DaveP
This uses a pair of 6CM7 TV tubes and it can output over a Watt of negative DC power into a 1k resistor in parallel with a 1uF cap. These $3 tubes are essentially half a 6CG7 plus half a 12BH7.
They operate completely in class A with the Edcor TX and are at ~70% of maximum dissipation. The feedback keeps the gain steady and brings the output resistance down to 100 ohms, the same as the Fairchild CV amp.
Best
DaveP