Found in an 1868 Mullard documentation this circuit has a dynamic range of 10 Hz to 25,000 Hz. Modern equivalent transistors can be used.
This is a bridge for the measurement of low value resistances and high values too. The circuit...
This frequency modulated light transmitter is from a 1990s documentation. The circuit may use...
We found this audio preamplifier circuit with a 741 operational in a 1976 publication. However,...