This very high input impedance JFET circuit was found in the 1995 Encyclopedia of Electronic Circuits Volume 5. The JFET is a general-purpose transistor as is the output transistor.
This circuit was found in an 80's General Electric documentation. The circuit uses uncommon...
This circuit was found in Electronics Today International of the 80's. The circuit uses still...
Using transistors common at the time (1960s) this amplifier with transformers in the output stage...