I want to to add about 20x gain to a microphone I have. I tested the following circuit with satisfactory results:
I was going to build a PCB for it, but then I realized I had no NE5532 around in SMD packaging. I found some LME49990, and reading the datasheet I found the following circuit:
So I modified it a little to get a balanced output. I just removed the second part that converts balanced to single ended:
Two questions: 1) Will this work? 2) why is R5 shared between both amps instead of using a resistor to GND like a traditional noninverting amplifier?
My rationale behind the two opamp version is that I have less components in the audio path, so, less chance of adding noise.
Bonus question: do I need to worry about DC here? Should I add coupling capacitors at the inputs?