This circuit was found in a Mallory documentation from 1968. The integrated circuit is of the time, unusual in our day. Input sensitivity is 20 mV for 2 W output.
We found the configuration below, with unit gain, in the National Semiconductor Linear...
This circuit is from an Electronic Design from the 90's. The main integrated circuit is uncommon...
This circuit appears on this site from different sources. This is from documentation from the...