he QH4 is a 4-channel headphone amplifier designed to distribute your audio to up to four individual headphones, each with its own volume control. Its compact design is perfect for use with any studio or desktop workstation, as well as with your laptop or smartphone when you're recording on the go.The four independent high-power amplifier channels deliver clean, crisp audio to up to four sets of headphones, operating between 16–600Ω. And power does not diminish even when all four channels are being used. Engineered with an ultra-low noise floor and wide dynamic range, the QH4 is a tremendous value compared to other headphone amplifiers on the market. Also, the QH4's Master volume control and Mute switch make controlling the overall level of your headphones a breeze.