K.GuSS DAC-K2 USB DAC Bluetooth 4.0 Audio Decoder Headphone Amplifier AIO TPA6120/OPA210/ fiber / coax / USB /Bluetooth / analog audio input amplifiersPacking listDAC-K2 × 1 USB cable × 1Antenna × 1Power × 1Packing × 1Headphone amp chip TPA6120A2, Enthusiast level. The machine uses dual power supply, allows full play to its performance, enables a wider dynamic range. It can well suit the 32-300Ω headphones.Bluetooth 4.0 + DAC decoder + OPA2107 amp-oneWm8728S Digital-analog converter chip. The chip produces warmer tone, significantly reduces the digital tone, sounds more natural and listenable.AKM4113VF digital signal processing chip. Fiber, coax, USB, Bluetooth, analog audio input amplifiers re all done by the chip DAC-K2 matched with STC15F2K32S2. So DAC-K2 signal switching is completed in digital signal.