You can take a flier on this. Cheaper than the NAD with USB input. The PC must serve the files though.
S.M.S.L AD18 HiFi Audio Stereo Amplifier with Bluetooth 4.2 Supports Apt-X,USB DSP Full Digital Power Amplifier 2.1 for Speaker,Small 80Wx2 Class D Amplifier with Subwoofer Output