I work on a project where i need to combine sound that comes from audio jack input (let say from tablet) with a sound we create from an MCU with DAC. So it basically means I need to sum the sound of : right speaker + left speaker + DAC.
Please see examples of what we did so far (notice we didn't yet chose the resistors for the op-amp):
How do you recommend to do it? Is op-amp is the right way? Do I need an amplifier at the output before I connect the it to a speaker? Can you advise on values for resistor/any other component/other solution?
I don't have much experiment in that area.