Behringer HA4700 High-Power 4-Channel Headphones Amplifier Professional, multi-purpose headphones amplifier system for stage and studio applications Highest sonic quality with virtually all types of headphones &gt;8 Ohms even at maximum volume 4 independent high-power amplifier sections provide up to four stereo mixes with individual balance controls Each input/aux section can be separately adjusted for 'more me' mixing Stereo Aux input for each channel allows you to mix in any instrument or sound source