FiiO E10 USB DAC Headphone Amplifier Volume Potentiometer, Barrier Free Design, Easy To Operate. Volume Digital Indicator, More Intuitive Bass Boost, OFF - 0dB;ON - +3dB, Built-In Bass Boosting Circuit, It's Different With Traditional Software To Set The EQ, The Effect Of E10 Will Be Better USB Digital Audio Converter To Coaxial Digital Audio Output; Line Output, Fixed Level Audio Line Output with Full Scale Support To Install Automatically Without Any Driver, Maximum Output - 96K/24Bit All- Aluminum Shell, Enhanced Anti-Interference Ability, Thus It's More Reliable And Durable