two tone electronic siren circuit

This is the circuit diagran of two tone electronic siren. The scheme is simple and easy to built, it based on two ICs with different task: produce audio signal and amplify the audio signal. List of Components: R1-R2-R3: 2.2KΩ R4: 1KΩ R5: 10K (potentiometer) R6: 470Ω C1 - C2: 10 uF C3 - C4...