Notes:
This circuit uses a couple of Op-amps to produce an
interesting sound effect. The left hand CA741 is wired as a
standard astable and produces the timing pulses, controlled
by C1, R2 and VR1. The output is fed via C2 to the second
op-amp and is also direct coupled via the zener ZD1 to Q1.
The right hand CA741 is configured as an integrator, its
purpose being to distort the output pulse from the first
op-amp. This produces a ringing effect on the output pulse
and gives the circuit a characteristic "tick" sound. The
output pulse at the first op-amp will cause the zener and Q1
to conduct on every positive transition. The 1k resistor R8
then acts as a low impedance shunt at the input of the
integrator and produces a characteristic "tock" effect.
R8,R7,R9,C3 and C4 may all be adjusted to tailor the sound
effect.
