This 2002 documentation circuit is suitable for automotive use. The circuit is based on an integrated that is not common today and has a medium power stage with a BD135.
This circuit is from 1977 documentation, but can be assembled with BC548 for Q1, Q2 and Q4, BC558...
Found in American documentation from the 90s, this circuit uses components that are still common...
This high impedance input amplifier is suitable for the use with piezoelectric sources such as...