This vibrato circuit was found in Motorola's 1966 documentation. The circuit uses transistors of the time that can be replaced with current common types. Power is done with 3 9V batteries.
This basic configuration can be found in a lot of articles on this site. In this case, the relay...
This circuit is from American documentation from the 1980s. The transistors are general purpose...
The circuit is simple, as it uses only one transistor and a relay that can be MC2RC1 or MC2RC2,...