1.The first stage is the RFI filter DC circuit. Through two pieces 50A bridge stacks and four pieces 35V2200UF capacitors, Filter the DC component of the AC power supply to suppress buzzing caused by saturation of the DC component transformer or increased static current. 2.Differential mode filtering, two differential inductors, differential mode filtering of AC power supply, to suppress medium and high frequency interference. 3.The first-level common mode filter, through the X2 capacitor and common mode inductor, combined into the first-level common mode filter. 4.The second level of common mode filtering, because of the use of two-stage filtering, so the filtering effect is better. In view of the problem of rapid transient group pulse interference with repetition rate of several kilohertz in some users, it can play an inhibitory role. 5.This module is used in conjunction with a decoder or power amplifier to filter the DC component of the power supply, eliminate and suppress the of the transformer, the high-frequency noise in the power supply, purify the power supply, and can significantly improve the sound quality of the power amplifier, enhance the resolution and make the background quiet. Name:Audio power amplifier filter Input Voltage:AC 110V-250V(Max 250V) Output Voltage:AC 110V-250V Filter Technology:EMI WIFI:No Grounding:Standard Grounding Type:Audio Power Amplifier Filter Working Current:4A Colour:Black Material:ABS Size:Board Size:108mm x 50mm Package Contents: 1 * Filter 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.