It's simple, it's compact - it's a 4 channel low noise headphone amp. Easy! Are you and your session players and bandmates tired of straining to hear underpowered headphones? We were too. That's why Jim Odom and his jambalaya-fueled team of engineers designed 150 mW headphone amps for the HP4 headphone-distribution system. These headphone amps are not just loud enough for session and stage use, they're loud enough to explode the oysters in a Po' Boy sandwich. Yet the sound is clear and clean, with a wide dynamic range. At last, everybody will be able to hear-assuming they are capable of hearing. Be careful with that level control!