With this circuit you can produce the sound effect passing from one channel to another. The circuit is from Mullard documentation from the 1960s. The transistors may be the BC548.
This old circuit for circuit breaker cars was found in a 1963 publication. The transistors are...
Several circuits similar to this one can be found on our website. This is from an internet...
The circuit of the figure can provide voltages of 5, 8.9 and 12.5 V at its output, all doing this...