Hi. Would I use an inverting or non-inverting op amp design for using an electret mic to flash a single led?

 

An electret mic and the resistor that powers/loads it are a faily high impedance (about 2.5k). If an inverting opamp is used then its low input impedance might reduce the output of the mic.
So a non-inverting opamp with a fairly high input impedance (12.5k and higher) is the best preamp circuit.

 

I will go with the non-inverting opamp then. You mention the preamp circuit, isn't that just the use of a vcc to a resistor and capacitor off the positive point of the mic? Are you talking about using the opamp as the pre amp?

 

Yes, the opamp is the preamp. It can also turn on the LED when the input signal is high enough.

 

Would I need a dual opamp for this?

 

If the output of the first opamp isn't high enough, you can trigger an NPN or use another opamp.

 

Thanks. I'm planning on using the LM358n. I might need some assistance on the schematic for this circuit.
Question: Does the electret mic create AC? Impedance relates to AC from what I understand. I plan on using a 9v battery for this, that's not AC.

 

An LM358 is too noisy (hiss), has high crossover distortion and has a bandwidth too narrow to be used as a mic preamp. Many low noise opamps are made. I use a TL071 single, TL072 dual or TL074 quad opamp that are low noise, have very low distortion and have a bandwidth that goes high enough for audio.

Here is a preamp for an electret mic:

 

Thank you for the preamp schematic. Would the 'hiss' of the 358 cause the led to flicker uncontrollably? I will look for the 071.

 

It depends on the amount of gain you set for the opamp.
What sounds and how far away are they from the mic?