Sound King 2 Channels 3W Pam8403 Class D Audio Amplifier Board 5V Usb Power He PAM8403 module is a miniature digital 2x3w class D power amplifier board, which can also work on USB power supply. It has good noise suppression when the input audio is via a sheilded wire. When working with a 5v power supply it can directly drive 4 Ω/8 Ω small speakers with big output power and good sound quality. This type of Class D Amplifier without LC Filter is Unique. It is achieved by double panel wiring. The super mini design is an added advantage since it can easily fit in a variety of digital products such as LCD TV Panels, Old speakers, portable mobile speakers etc. Length - 2.11 cm Width - 1.85 cm Weight - 5 g Class - D Please Note: Do not mix the "negative" of the left and the right output channel with the "negative" of the power supply, otherwise it will burn the IC rendering the module useless. Also do not switch on the board without the speakers connected i.e with no load since this will also heat up and damage the IC. Try to use the recommended power supply guidelines. To obtain a noiseless amplification please ensure that the input audio source is properly shielded.