FiiO E09K High Output Desktop Headphone Amplifier with E17(E17K) Alpen II Portable Amplifier with RCA-to-RCA Cable Kit Device uses a Texas Instruments TPA6120 Integrated Circuit, which is their main power amplifier IC with a low noise level, low distortion and a high conversion rate TI OPA2134+TPA6120 chip combo allows the headphone amplifier to have low noise, low distortion and high power E09K and E17K with Gold Plated RCA-to-RCA connector cable included. Dual-channel power output for two headphone plugs. It features both 1/8" (3.5mm) and 1/4" (6.35mm) type headphone output jacks Fiio E17K docking base for E17K USB DAC Headphone Amp and external USB soundcard. The dock also facilitates charging and USB synchronization data exchange with computer Features On/Off/Mute function for amplifier output protection with sealed, low-noise ALPS potentiometer