A stereo power amp is required to provide signal to the HB1XL. 50 Watts is the maximum recommended power to prevent damage to the headphone isolation resistors. A single knob, stereo pot controls the level in the left and right channels simultaneously. Premium quality, sealed 2 Watt, audio taper pots provide reliability and precise level control. A stereo/mono switch combines left and right channels into both earpieces. Both ¼” and 3.5mm headphone jacks are provided. Parallel wired female and male XLR input/loop thru jacks can be used for "Daisy chaining" modules. A permanently attached belt clip provides a convenient method of attaching the HB1XL for easy access to the controls.