Charles Interpreters Box - 

The headphone amplifier on the Charles is very high performance delivering high intelligibility on a variety of headhones and headsets. Headphones between 32-1000 ohm are automatically balanced to give a consistent output level across the range of the volume control. Stereo and mono earpieces can also be used. A broadcast headset can be connected to the Charles with a 3 pin XLR mic input and a 6.35mm headphone connection. A separate microphone can be connected via the XLR input and separate headphones can be connected using the 6.35mm or 3.5mm connection. The 3.5mm headphone connection will allow the interpreter to use in ear headphones or earpieces if that is their preference.