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Help in designing a VU meter circuit w/ an electret mic.
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K-Experiment:
I'm still a beginner in designing my own circuits.
can you help me with the design of the circuit if there is something to change?
also, I have some questions like:
Can it all operate in 5v? it says in the datasheets that the ic's can operate on 5v but I'm afraid that the voltage is too low and can cause distortions.
Do I need the precision full-wave peak detector? I was told that it can help smooth out the audio from the op-amp.
 
fcb:
Assuming there a speaker missing in your design? (hence the LM386 and huge ac coupling capacitor).

Let's sort out the front end and get to the bottom of what the overall device is trying to do before setting the rails.

K-Experiment:
There wont be a speaker.
it will just measure how noisy the room is or see how loud the music in the background is played.
fcb:

--- Quote from: K-Experiment on April 29, 2020, 02:32:15 pm ---There wont be a speaker.
it will just measure how noisy the room is or see how loud the music in the background is played.

--- End quote ---
Get rid of the LM386 and humongous coupling capacitor and replace with another pair of LM358 stages - probably a gain of 50-100 will be sufficient (so each stage needs sqrt(50) to sqrt(100)=7 to 10).

Assuming you are trying to make the whole circuit work on a single rail? 5V can be done - 9V might be nicer.
K-Experiment:
Yes I am using a single rail.
I currently only have one lm358 and one lm386 but I do have a few lm324s, should I use the lm324?
I checked the datasheet for the lm386 and I can set the gain to 50. will that work instead of using a second lm358?
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