THX AAA 788+ Chips: The THX AAA 788+ chips used in the FiiOK9 Pro ESS Desktop DAC and Amplifier provide exemplary details and dynamics no matter if you are using low or high-impedance headphones Precise Design: Fully differential signals go through the DAC, volume adjustment, and amp for a truly balanced design. Such a design ensures minimal interference between different components in order to fully maintain all details and large dynamic swings in music for unmatched sound quality Power Supply: Electricity is the mother of sound, so special attention was paid to optimize the FiiOK9 Pro ESS Desktop DAC and Amplifiers power supply to ensure excellent sound. The FiiO K9 Pro ESSs linear power supply, with its low-frequency transformer and 4 massive 4700uF capacitors, makes sure that the rest of the system gets abundant clean power