need more help with sound trigger

[audioguru]

It is good that the first transistor has a bypassed emitter resistor for good DC stability.
The second transistor is not needed.
Maybe an adjustment should be available to set the sensitivity.

Please connect a resistor in series with the base of the 3rd transistor to limit its base current.

 

[gvi70000]

sorry,
I'm a little bit confused... Correct me if I'm wrong

1. Replace R3 10k with a pot (i think same value...maybe 15k)
2. I have to connect a resistor at the base of Q2 (because i only have 2 transistors in the circuit) but if i put a 1k resistor the amplification after Q2 will be smaller than the on give by Q1 - i didn't simulate the circuit but i think that the Vout from Q2 is smaller with at least 0.7V

 

[audioguru]

I don't know why you are using a preamp with two transistors when only one properly biased transistor is needed.

If the preamp works then don't change its parts, instead make the R8/R9 voltage divider adjustable for sensitivity.

 

[gvi70000]

Thanks,
I will try that and let you know the result.

I know that i'm annoying with my questions, but this is by far the most complicated project that i made so far. I tray to learn by myself but some times i get no results...and i become annoying.
Thanks again.