I am new to analog audio interface design. I am trying to get a line level output from a amplified headphones level output. I want both of the output to work at the same time in order for the user to be able to listen through headphones while recording the line level output.
Would something like this work ? (coupling capacitors not included):
I1 being the output of my headphones amplifier, R4 or R5 being a pot to adjust the line level output.
My guess is that the high-Z input of the opamp will not disturb the headphones output but I also wonder if the headphones amplifier can fry the opamp if the headphones are not connected.
I could have taken the line level output before the amplifier but the input of the amplifier will most likely be differential audio and it makes it a bit more complicated for me.
I would like to have advice on whether or not this can be a suitable circuit and also what are the best practices and/or things to avoid when it comes to analog audio interface.