Can use the computer USB port 5V power supply or using a mobile phone charger USB port 5V power supply
Battery power can also be used
High efficiency: 90%
Can provide 3W (left channel) + 3W (right channel) output power in the 4Ω load and 5V power supply conditions
A class, B class amplifier such efficiency is only about 30%
D class amplifier is highly respected today
D class amplifier efficiency is extremely high, not because of temperature affect the sound quality
But do not add heat sink and take less space noise cancelling circuit was built in the amplifier board
Power on / off without pop noise
Module has a short-circuit current protection and over-temperature protection

Specification:

Operating Voltage: 2.5V ~ 5.5V
Speaker With: 4Ohm ~ 8Ohm (recommended: 4Ohm)
Speaker Power: 2W ~ 8W
Size: 21 x 18 x 3.4mm (L x W x H)
Net Weight: 1g

Application:

LCD TVs, monitors
Laptop
Portable Speakers
Portable DVD players, game consoles
Phone / speakerphone

Note:

First turn OFF and then powered speakers , or likely to cause damage to the chip;
Because digital volume control module has a great gain , so do not let too much leaving the audio signal input signal cut limiter.