The circuit design of this machine is relatively complex. It uses single-ended to balanced circuits, positive and negative boost circuits, and high-current output driver chips to make the sound quality of this machine warm and durable. The single-ended to balanced circuit has good anti-interference ability, and long-line input No time loss; The 5V power supply can be powered by a power bank or a high-quality charging head. The circuit of this machine has been optimized, and it is still recommended to use a high-quality power supply. Stereo two-channel, four in and four out; Input one channel and four channels are output at the same time. If you input more than 2 channels, the output is mixed sound. The input volume and output volume of each channel can be adjusted independently; Input impedance: 10K, output impedance: 16 ohms-600 ohms; Gain: 0db, input and output signals are the same; Working frequency: 20HZ-20KHZ; Power supply: DC5V-12V, working current: 5v-650ma, 12v-240ma; Material: Metal colour: black Package Contents: 1 x Stereo Mixer 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.