Non Inverting Amplifier (CB6437E)

This non-inverting AC amplifier was found on a Popular Electronics. The setting applies to any operational amplifier.

500 ohms Audio Amplifier (CB13668E)
We found this audio amplifier stage with 500 ohms of input impedance in an old American...
Car Sound Booster (CB18799E)
Although the author of this circuit indicates a power that he does not really have, considerable...
Dual temperature monitor (CB21377E)
This circuit was obtained from a 1967 GE SCR manual. It is intended for controlling relays...