I'm trying to make a simple circuit that will allow for the combining and recording of both sides of the conversation by tapping into the connection between a cell phone and a headset.
For convenience sake, I want to also use a spare cell phone as the recording device due to portability,etc. I am using iPhones for the cell phones in this application, although that shouldn't matter.
NOTE: The iPhones provide approximately 1.8V to the microphone to power it, thus my decoupling capacitors on both the input and output. The 4.7K on the output is to trigger the recording iPhone to switch over to external mic mode, otherwise it will only record the internal mic and ignore the input signal.
I've tried designing this to the best of my knowledge and understanding, however I am not getting anything on the outputs. I've checked the input with an oscilloscope and I'm getting a good signal at the opamp input pins, but nothing on the other side. I've tried changing out the IC and still nothing, which I'm guessing there's a flaw in my design since I don't fully understand each component's role/effect in the circuit beyond basic theory. Any help would be awesome and much appreciated.