D4 sound card adopts CM6642 audio decoding chip, supports 24Bit 192kHz output, good sound quality Lossless output. It can be directly connected to the computer with a USB cable. D4 can connect various Amplifier or active speaker with output, can also be used as a power amplifier to connect various earphone. The headphone amplifier adopts 5532 chip, the sound field is deep, transparent and bright . With secure and reliable USB Type B port, plug and play, suitable for most operating systems, such as 2000, WIN7, WIN8, WIN10. As an such as , no driver is required. Note: If there is no sound output after connecting to the computer, please go to the computer control panel-Sound settings option and set it as default. Headphone output power:150MW+150MW Amplifier Impedance:16-350 ohms Distortion:+N:0.004% (RL 10 kn) Distortion:+N:0.020% (RL = 32 0) Signal-to-noise ratio: 99 dB Colour:Black Material:Aluminum alloy Size:70x70x40mm (LxWxH, including knob) Package Contents: 1 * Headphone Amplifier Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.