ART HEADTAP HEADPHONE CONTROLLER Driving headphones from speaker lines can be problematic. Being deafened of having the cans incinerated on your head are just two possibilities!! The HeadTAP is designed to connect headphones to a speaker output or a line level signal source. It is designed to allow many boxes to be connected in series via the stereo/mono loop jacks. Apply up to two sets of headphone and adjust with a single control. It is more convenient if both sets of headphones are the same or similar impedance. Passive so no batteries or power supply is required. All inputs/outputs and function knobs are clearly labelled.