One input and four output, each output volume is independently controlled. Built-in mcu control circuit, perfect control of the impact sound of the power-off, static effect of the switch. With a 10dB, gain switch, you can increase the following volume, add the level to the device with lower output level, increase the volume Frequency response 20-20kHz 0.1dB, distortion 0.0001 percent output phase and input phase are the same Each channel is independently processed by an op amp, and does not interfere with each other. The machine is equipped with TI's NE5532. The Buyer can replace different op amps according to their own preferences. The op amp supply voltage is 12v the op amp is positive. Jinggong produces gold-plated sockets with good contact and resistance to plugging Solid-state filter capacitor, stepless audio coupling capacitor, Tk audio audio coupling, extremely fever Gold-plated socket, good contact, brushed aluminum casing, laser-engraving, high-grade, beautiful, atmospheric Power supply voltage: DC DC12V, current: 1A or more than 1A (Not include the power supply) Colour: Black Material: aluminum Size: 11.7 x 10.7 x 3.5cm Package Contents: 1 x HUB Audio Distributor Only the above package content, other products are not included. Note: Light 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. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.