The integrated circuit of this amplifier is not very common today. The output transistors can be TIP31 and TIP32 in heat radiators. The circuit is from the 1977 National Semiconductor Audio Handbook.
This circuit is from the 1972 Linear Data Book of RCA, but it can be made with more modern...
I found this simple circuit from an English magazine from 1984. The circuit can be easily...
We found this logic level tester in a 1976 documentation. The circuit is powered by the voltage of the...