Sound Devices HX-3 3-Channel Portable Headphone AmplifierThe compact HX 3 Headphone Distribution Amplifier is the perfect accessory to quickly provide three high performance stereo headphone feeds with individual level controls from line level sources. The HX 3 can produce very high headphone levels with extremely low noise and distortion. Great for radio, television, film, and music production applications, the battery powered HX 3 accepts balanced XLR line level inputs or unbalanced 1 4 inch and 1 8 inch