We found this circuit in Mullard's 1960s transistor manual. No information about transformers is given. Transistors are germanium types of the time.
This circuit is indicated to operate from high impedance sources as piezoelectric transducers....
We found this circuit in a Motorola publication from the 70s. The circuit can be implemented with...
This double bench source has a fixed voltage output and an adjustable voltage output with current up...