A dub siren is an electronic circuit that emulates a mechanical air horn siren by oscillating electrons and ampliyfing the signal into an audible waveform.
A dub siren is traditional in dub reggae productions and common in selector performances and sound system preamp rigs.
First we take 9V from a conventional power source through a diode, resistor and capacitor.
A timer, an operational amplifier and a few resistor/capacitor arrangements produce a waveform shaped by the combination of settings on the potentiometers.
A sub-circuits produces a visual on the modulation rate.
The signal goes through a second timer that either compresses or expands the wave vía a potentiometer and it's corresponding resistor/capacitor arrengements to modify the frequency.
A switch allows the signal to either momentarily or continously go through a potentiometer, resistor and capacitors that allow the amplitude to be modified before sending it to the output jack.