Independent volume control for each channel1 input with 6.3 toman mm stereo jackInput impedance 100 ohms8 outputs with 6.3 mm stereo jacksOutput impedance 80 ohmsDimensions (W x H x
D): about 19.6 * 5.7 * 3.1 m12 volt power supply includedCombined useYou can use this ultra-compact stereo headphone amplifier with any of 8 headphones simultaneously. Eight listeners in the studio can listen to the main mix while recording, and each listener can adjust their own volume using a dedicated output level control. The HA800 contains 8 high-power stereo amplifiers, which can maintain the highest sound quality at the maximum volume. The ultra-low-noise 4580 op amps have outstanding audio performance, and they are the same op amps found on full-size audio equipment, and a DC 12V adapter is also available