Stereo Audio Preamplifier; The amplification circuit adopts the classic NE5532 operational amplifier, which can drive headphones, power amplifier Active Speaker; The audio circuit has relatively high requirements for the power supply. Please use a low-ripple power supply. Poor power supply is likely to cause . The audio connecting wires should be shielded wires. Frequency response: 20Hz-20KHz Power Supply: DC 9V-19V; Supply Current: 8 mA; Power Consumption: 0.9 W; Amplification Gain: 20 dB; Input impedance: 10K Output impedance: 600 Input and Output Interfaces: 3.5 mm, ; The 3.5 mm interface and the interface are designed to adapt to different situations. They cannot be used simultaneously. Just choose one of them. Plug Type:US Plug,it applies to Canada, India,Mexico, Thailand, the , the Philippines,Taiwan and so on. Voltage:AC100-240V Color: Black Material: Metal Package Contents: 1 x Audio Preamplifier 1 adapter 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.