Product DescriptionBEHRINGER POWERPLAY HA4000Ultra-Compact 4-Channel Stereo Headphone AmplifierUltra-compact headphone amplifier system for studio and stage applications4 independent stereo high-power amplifier sectionsHighest audio quality with virtually all types of headphones even at maximum volumePhones Level control per channelDC 12 V adapter includedHigh-quality components and exceptionally rugged construction ensure long lifeConceived and designed by BEHRINGER GermanyIf 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 NowYou 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 ValueWhen a recording session calls for everyone's heads - and ears - to be in the game, the HA400 is a real lifesaver. Hearing is believing - check out the amazing HA400 at a BEHRINGER dealer near you.Amazon.comIf 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.A Simple Solution Grab this super-compact amp during your sessions to power practically any headphones--four of them at the same time, to be exact. This allows four people in your studio to listen to the main mix while recording, and each listener can determine their own volume level using the dedicated output level controls. Quality Amplification The HA400 contains 4 high-power stereo amplifiers that maintain the highest sonic quality even at maximum volume levels. These ultra-low-noise 4580 operational amplifiers are included for outstanding audio performance--the same op amps found in "full-size" audio equipment. What's in the Box Behringer HA400 4-Channel Stereo Headphone Amp, Power Adapter, User's Manual