My first cricket circuit board arrived today and it chirps!
A little circuit board with a series of astable multivibrators that generate a cricket-like chirp through a piezo electric buzzer.
Astable multivibrator circuit built with discrete transistors. The circuit generates a waveform that sounds like a cricket when applied to a piezo electric buzzer. Kelly Heaton, 2018
I did make one error in my schematic, which involved the reversal of the PNP transistor (3906). Thankfully, the wiring worked perfectly when I turned the PNP in the opposite direction.