The 3.5 mm plug from the headset should be plugged into the in-line amplifier’s jack. The amplifier’s plug should then be connected to the headphone jack of the computer. The USB from the amplifier should be connected to a USB port in the computer. Continue to either Windows 7 or Mac if applicable. Windows 7: After following the steps to connect the device to the computer, go to the Start menu and select the Control Panel. In the Control Panel select Sounds and make sure that you’re in the playback tab. Make the headset the default playback by right-clicking Turtle Beach PX22 headset and selecting “Set as Default Device”. Next go to the Recording tab, right-click on Turtle Beach PX22 microphone and choose“Set as Default Device”. Mac: After connecting the device to the computer in the above steps, go to the Apple menu. In the Apple menu go to System Preferences and then Sounds. In Output select Turtle Beach PX22 as the default speakers. In the Input tab select Turtle Beach PX22 again as the default microphone.