Before trying different amplifiers, try and reduce the resistors for IC2 by a factor of 10. I've used 741 before and found that at even 1,000 Hz frequency the large resistors make the amplified signal noisy. You have a scope so you can compare how your signal from the first stage looks like with two sets of resistors. If you do 47K and 1K then you will get the same amplification but hopefully less noise.
When everything is cooperating, this circuit can generate periodic pulses with the same frequenncy as the input signal's fundamental frequency.