New USB speaker solution MK909D, 1W output power per channel

New USB speaker solution MK909D.
# Use the latest USB DAC chip, support USB1.1, USB2.0 interface.
# 48K DA sampling, built-in stereo Class D audio amplifier, 1W output power per channel, no longer the problem of low output power of other USB speaker solutions.
# Built-in 64-level volume control with memory function; supports three volume adjustment methods (A) touch button; (B) potentiometer; (C) encoder. Support output mute function.
# The peripheral circuit is simple: 2 10UF, 2 4.7UF, 1 2.2UF, 4 capacitors below 0.1UF, 4 resistors, 1 LED, 1 24M crystal. Due to the built-in stereo Class D audio amplifier, the output does not require Use large electrolytic capacitors for DC blocking, which is low cost.
# The status of the work indicator light can be selected between steady light and flashing.
# The IC is packaged in SOP28 with heat sink and is small in size.