The circuit is from the MC1539 manual, an operational one close to the 741. The transistor admits equivalent and must be mounted in a good heat sink.
This interesting idea was obtained in a 1982 documentation and can be used for special effects in...
This is another of the many circuits we have with the 8038. The circuit is from the Radio...
This LC oscillator was found in English documentation from the 1990s. JFETs may be general-purpose...