Found in an Electronics World of 1966, this circuit makes use of FETs of the time. Modern equivalents can be used. The high voltage supply suggests its use with tube amplifiers.
This circuit was found in the June 1991 issue of Radio Electronics magazine. The circuit uses two...
The MOSFETs are of the type of power and the resistors have their values between 1 k and 10 k for...
In the figure we have the way to use an LED to increase the voltage of a zener. The increase...