This circuit was found in documentation from the 90s. The components used are not common today. The circuit can be adapted to employ modern equivalent components.
We found this configuration in a documentation for radio amateurs from 1974. The circuit can be...
Texas Instruments' low power operational amplifiers OPAx196 can be found on Mouser Electronics....
This low power amplifier circuit for speaker or phone is from the Philips Databook of 1990. The...