This circuit is from the 80's documentation. The integrated circuit is from the time but can be implemented with modern equivalents. The power supply must be symmetrical.
This circuit produces the sound of percussion such as blocks, drum, bell, etc. The frequency...
We found this oscillator in a publication from the 1960s. The frequency is around 600 Hz with the...
Found in a Popular Electronics from 1992, this circuit uses a PLL567 in an audio meter bridge that...