This circuit for the very low frequency range was found in the Radio Electronics magazine of February 1983. The components are according to the frequency range to be amplified.
In this amplifier, the supply voltage is 35 V and the input resistance is 2k2. Equivalent...
This high speed laser diode driver was found in a 1980s documentation. Power FETs can be replaced...
This instrumentation amplifier with differential inputs was found in documentation from the 90s....