How to Wire a Mono Cable to a Stereo Jack | It Still Works How to Wire a Mono Cable to a Stereo Jack by Joe Murray . Plug the mono plug at the end of the cable into the mono-to-stereo adapter. Step 2. Plug the cable with the mono-to-stereo adapter into the stereo jack. Play a monaural signal source and listen to the individual speakers. Sound should be coming through each speaker at the same volume Xlr to Mono Jack Wiring Diagram | Free Wiring Diagram Collection of xlr to mono jack wiring diagram. A wiring diagram is a streamlined conventional photographic depiction of an electric circuit. It reveals the components of the circuit as streamlined shapes, and the power as well as signal links between the devices.