RACOON Shange SG200 24Bit/48KHz High-Quality USB DAC Tube Headphone Amplifier black Usb 2.0 ports, stereo audio D / A decoding Headphone output impedance adaptation range 8-1000, the output power peak - range 2.7W-100mW 24-Bit Dac Usb decoder , using Micronas UAC3553B high quality decoder integrated chip Up Support 24-Bit audio playback , the conversion rate for the 6.4-48KHz 12AT7/ECC81/6201/GT-12AT7/6C22D/12AZ7 tube universal, you can replace upgrade