Harman Kardon HK 3700 2-Channel Stereo Receiver with Network Connectivity 85W X 2 high-current, ultra-wide bandwidth amplifier Frequency Response (@ 1W) 10Hz  130kHz (+0dB/3dB).Complete connectivity including a phono input, FM/AM radio, home network DLNA, vTuner Internet radio, iOS Direct with built-in DAC (digital-to-analog converter) or audio file play via USB High-resolution DAC, featuring a 24-bit/192kHz sampling rate Subwoofer output.If unit does not respond to remote commands then make certain the front-panel sensor is visible to the remote or connect an optional remote sensor Harman Kardon remote app provides control through iOS and Android platforms