Based on the TCA6600 or TCA5500 this circuit was found in a 90’s European documentation. The integrated circuit used is not very common today.
National Semiconductor suggests this circuit in its 1994 Linear Applications Handbook. The D3...
Found in the April 1980 issue of Radio Electronics magazine, this stage uses transistors from the...
This circuit is from an Italian publication called Fare Elettronica from 1987. What we have is an...