High quality filter power supply. The four pins of rectifier respectively in parallel connect with decoupling capacitor, which can effectively eliminate the high frequency interference of AC power grid. Now the clutter interference of power grid is very small and the voltage is quite stable. So the item has better performance.The chip has high conversion rate and strong drive ability. The frequency band is wide and noise is very small. Features: 1, Power supply circuit adopts full bridge rectifier. 2, Effectively eliminate the high frequency interference of AC power grid. 3, Chip has high conversion rate and strong drive ability. 4, Better performance,noise is very small. 5,Sound warm and distorted, high fidelity Specifications: Working Voltage: AC double 12-18V tune type: Low/Middle/High Pitch/Volume Channel: Double channel Audio Input: RCA sockets Audio Output: 3P terminal Input Voltage: 3P terminal Size: 105 mm x 54 mm Weight: 75g Package includes: 1 x HIFI Preamplifier Control Board Module Note: 1, Please allow 1-3 mm error due to manual measurement. Thanks for your understanding. 2, Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard.