Found in documentation two years 80, this toy instrument uses an integrated circuit little commonly. As notes are given the values of key series resistors on the keyboard.
This circuit was published in Radio Electronics Magazine in February 1958 using the well-known CK722,...
This circuit was found in a 1980s documentation. The IC is the 7400 and should be powered with 5...
The voltage gain of this amplifier is 10 times. This gain is given by the relationship of values...