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.
In a modern version this circuit can use an LED in series with a resistor in place of the lamp. The...
This is the single-sourced version of the previous oscillator. Frequency can be changed by...
This circuit is from the documentation of the 90s. Thus, the integrated circuit used is not common...