I have a differential input, differential output amplifier being driven by a single ended output microphone. Here is the circuit -
The output is noisy and I suspect it has something to do with both inputs being AC coupled.
The Microphone has a DC output of 1V, hence the AC coupling.
If I short out C9 so that the inverted input of the amplifier is directly coupled to GND, the noise goes away. However this give me a permanent differential voltage on the input of 1V.
Is there a correct way to AC couple pseudo differential output to a differential input?