Below is a diagram showing how to connect your X42 to a PS4 (2013) or PS4 Pro Console.
What you'll need:
PS4 Talkback Cable (2.5mm to 3.5mm cable)
Note: You must connect the optical cable to a TV optical output (if available) with the slimmer PS4 (2016). You can find more information about this here: New Slimmer PS4 (2016) - Headset Compatibility