Abstract: The present invention has all the properties and capabilities of a standard direct-box, which is an audio adapter circuit in a rugged chassis. It allows high-impedance stereo headphones to be connected. It comes equipped with a switch that turns the signal to the exterior sound system on/off without interrupting sound to the headphones. The present invention also comes with a locking cover, which prevents inadvertent operation of additional switches, such as a ground lift switch or attenuation level switch. The cover also functions as a mounting structure.