The 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 QH4 features two balanced 1/4 inch. inputs to connect with your mixer or recording interface, as well as a stereo 1/8 inch. Aux input that's perfect for playing music via your smartphone or another line level device. The four independent high-power amplifier channels deliver clean, crisp audio to up to four sets of headphones. 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.