I'll break it down as much as I can: Basically the irig dongle plugs into the phone and into a mixer or mic channel. A cable goes from the irig head phone output to a mixer channel. You will need a ⅛ inch TRS to ¼ inch cable to do that. You can find those in y cables as well, otherwise just pan all the way left if it is a single cable going into a two channel input. To get sound back to your caller the find guitar looking input on the irig2, plug one end of a ¼ mono cable into that, and the other into an FX send or headphone amp. If you plug it into an FX send turn the phone channel fx knob all the way down or else they will hear their own voice. The thing with the headphone amp is you don’t need to mess with that, but make sure the headphone amp volume isn’t too loud for your caller. (You'll just have to ask them) If you are doing the headphone amp method, If you have a mixer you record that has an SD card you record to, pan the channel all the way left, even if it is a y cable, or else the recording on the SD will echo. Make sure the gain on the irig2 is about halfway.