Inverter Amplifier (CB6431E)

This high input impedance circuit was found in a Popular Electronics of the 90s. The circuit supports modern operational.

Integrator with bias compensation (CB3939E)
We found this circuit in an old publication. The circuit can be implemented with modern equivalent...
High Impedance Differential Amplifier (CB4896E)
Operational amplifiers used in this 80's circuit is not very common today, but the setting can be...
7 W amplifier (CB8946E)
No information is given about the transformers in this circuit suggested by Motorola in a 1968...