Samarth Enterprises Digital Power 2x3W Class D Amplifier Board Features: miniature digital power amplifier board 2x3w class d power amplifier board, can work on usb power supply. good noise suppression input audio should be via sheilded wire dual channel stereo output 3 w + 3 w power works with 5v power supply can directly drive 4 O/8 O small speakers big output power, sound is good. unique without lc filter class d digital power board can use computer usb power supply directly double panel wiring, super mini design, can easily fit in a variety of digital products high amplification efficiency made with solid plate welding machine super size: 1.85 x 2.11 cm.