i made the clapper too but is no change in operation if i put pin 13 on ic3 to the ground to make the microphone more sensitive you just have to do a simple 1 stage amplifier with an transistor, i'll atach the schematic below, i wanna know how did you manage to get it working, what modifications did you do?
build just the preamplifier stage

 

Thanks for the advice. Does your circuit make the red led light on first clap? Try swapping over the 555s to see if second one is faulty if the red led works. What stage of the circuit is faulty for you? Can you check operation of the transistor switching the servo? IC3 is CMOS so static sensitive - perhaps your one is fried? Hope you can get it going. If/when I pull my one out of the draw and try your suggestion I'll report on what happened

 

the clap switch works great with tl062 microphone preamplifier and it has high sensitivity by adjusting the gain pot on the tl062 board, i used a 500k ohm pot. good luck to others that are trying to build this wonderful projectps: i build the two 555 and cd4017 clap switch

 

thanks for everything.</p>and pls try other super cool microphone preamplifier that i've made with a op amp and works super cool rather that transistor one and please use a TL062 or a TL072 and has a super amplification and low noise, i used that on my clap switch, and at the gain in the schematic place a 500k ohm pot and trim it for maximum sensibility i'll atach schematic and pcb layout</p>

 

Instead of wasting one opamp of the dual tL072, why not use a single TL071?

 

in my country a tl062 is cheaper than a low power transistor... so i use circuits instead of transistors a tl062 is less than a quarter of a dollar

 

Me again,
I've bought a better quality electret microphone and tried again with the circuit at original design. I can get better results but not good enough still. I'm afraid I am not knowledgable enough to redesign an additional amplification circuit/ stage one amplifier/preamp as was recommended in the above posts, so would appreciate if someone could please show me what to make and how to fit it into the circuit I already have. Thanks

 

hi, i know im a year too late but i came across a parabolic microphone project in an electronics projects for dummies book which claims to let you hear over 100ft or something with a parabolic dish..i have only made the circuit part (works on breadboard but not pcb ) and its a pretty good amp circuit i think. the output could easily be replaced with the mic on this circuit.

and thanks for your fix, Johnnz - life saver!
3 of my recent projects failed and this is the first to work!

i might test the amp circuit with the clapper later today and will let you know how it goes. ill also post up the circuit for the amp.

 

heres the circuit: Parabolic Microphone Circuit
R1 = 5k6
R2 = 10k pot
R3 = 10R
C1 = 0.1u
C2 = 10u (e)
C3 = 10u (e)
C4 = 100u (e)
C5 = 0.047u
IC1 = LM386N-1
Mic = Electret

Worked great for me although i had to take it of because it was too sensitive.. lol