This circuit uses an amplifier from National Semiconductor, uncommon nowadays. The numbers in parentheses are for the second channel. The circuit is suitable for old tape recorders.
This circuit was found in the January 1989 issue of Radio Electronics magazine. The circuit sends...
This simple audio generator with the 741 was found in a 90sTexas Instruments. The circuit...
In fact, this 1994 circuit uses a scale of LEDs to indicate the pulse rate applied to its input....