This sound effect circuit uses only one integrated. We found it in a 90's EDN. The effects can be modified by changing the components.
This circuit was found in an old Poptronics but is still current as transistors can be replaced...
This 1968 Hughes circuit uses period components and operates at 8 Hz. Current equivalent...
This 100 kHz oscillator was found in a 1966 Motorola publication. The transistors are of types...