A second point relative to "phase reversal" would be "relative to WHAT??? For a single audio signal what would be considered the reference??
Of course, if the circuit is part of a network analyzer system, then phase inversion could matter quite a bit.

 

Do we need 10uF capacitors at the input? I think 1uF Non Polarised capacitors are better.

 

Do we need 10uF capacitors at the input? I think 1uF Non Polarised capacitors are better.

1μF plastic film capacitors are better
1μF X7R dielectric multilayer ceramic capacitors are worse. (If you use them, you might not need the microphone!)

 

Do we need 10uF capacitors at the input? I think 1uF Non Polarised capacitors are better.

The inputs from the organ and drums are in 0-3V range, and i thought that the input capacitors would remove the dc offset

 

The inputs from the organ and drums are in 0-3V range, and i thought that the input capacitors would remove the dc offset

Yes, they do, but do you need such high values? The input is to an Op Amp.

 

That's the value i saw in various circuits online and i just used it, it worked and didn't i didn't give it a second thought.

 

Any capacitor in series with the signal is an RC high-pass filter. It determines the low frequency cutoff.

Calculate the low frequency cutoff for 1 μF and 10 μF capacitor.

 

Any capacitor in series with the signal is an RC high-pass filter. It determines the low frequency cutoff.

Calculate the low frequency cutoff for 1 μF and 10 μF capacitor.

Is'nt this an Audio system? Surely we are not dealing with 0.33 Hz!