For the record, I just noticed what appears to be a boo boo in the paper by Mr. Whitlock of Jensen Transformers.
In figure 2, which I referred to earlier, the formulas for Vx and Vy should have CPS1 and CPS3 in their numerators, respectively, rather than CPS2 and CPS4. That follows from the fact that the voltage divider effect between the two capacitances in each component will be dependent on the reactance of the capacitors (1/(2piFC)), not on the capacitance values themselves.
Therefore I retract my previous theory about CPS4 of the unused amplifier causing Vy, and hence the hum level, to worsen.
Best regards,
-- Al
In figure 2, which I referred to earlier, the formulas for Vx and Vy should have CPS1 and CPS3 in their numerators, respectively, rather than CPS2 and CPS4. That follows from the fact that the voltage divider effect between the two capacitances in each component will be dependent on the reactance of the capacitors (1/(2piFC)), not on the capacitance values themselves.
Therefore I retract my previous theory about CPS4 of the unused amplifier causing Vy, and hence the hum level, to worsen.
Best regards,
-- Al