This circuit makes use of a specific 80's component and was found in an American manual of the time. A matrix keyboard allows you to select one of several music programs.
This circuit was found in the January 1980 issue of Radio Electronics magazine. It is a digital slot...
This circuit was found in a 1990 Electronics Handbook. The transistors can also be the BC548 and...
This amplifier circuit is from a 1952 documentation. The frequency of the amplifier signal depends on...