Behringer Microamp HA400 Ultra-Compact 4-Channel Stereo Headphone Amplifier BEHRINGER POWERPLAY HA4000 Ultra-Compact 4-Channel Stereo Headphone Amplifier Ultra-compact headphone amplifier system for studio and stage applications 4 independent stereo high-power amplifier sections Highest audio quality with virtually all types of headphones even at maximum volume Phones Level control per channel DC 12 V adapter included High-quality components and exceptionally rugged construction ensure long life Conceived and designed by BEHRINGER Germany If you're tracking more than one musician at once, or if everyone in a group wants to listen to a playback, you need a monitor distribution system. The compact, flexible HA400 can power up to four pairs of headphones and up to four independent volumes. Altogether Now You can use this super-compact stereo headphone amplifier with practically any headphones - four of them at the same time, to be exact! Let up to 4 different people in your studio listen to the main mix while recording, and each listener can determine their own volume level using the dedicated output level controls. The HA400 contains 4 high-power stereo amplifiers that maintain the highest sonic quality even at maximum volume levels. Ultra low-noise 4580 operational amplifiers are included for outstanding audio performance - these are the same op amps found in "full-size" audio equipment - plus, a DC 12-Volt adapter is included. Great Sound, Great Value When a recording session calls for everyone's heads - and ears - to be in the game, the HA400 is a real lifesaver.