This amplifier is from Motorola documentation from the 70s. The circuit uses transistors from the time, which are not common today, such as the SE7005 or 2N3916 at the output.
This circuit was found in an American publication called Ham Radio. The circuit uses still current...
From an audio signal, this circuit gets two signals of the same amplitude and opposite phases....
Found in an Electronic Design from 1968 this circuit generates a linear sawtooth signal modulated...