**********12AU7 vacuum tube MOSFET Class A amplifier without any OP amp or IC; Pure warm and sweet tube sound*****Unlike acrylic shell, PCB shell is more expensive and solid and has fine anti-interference and shielding*****Input: 3.5 mm (phone/MP3/palyer) & RCA (CD player/computer);
Output: 3.5 mm& 6.5 mm headphone port
& RCA*****RCA LINE OUT: Can be used as a preamaplifier for other amplifiers or active speakers*****12AU7 vacuum tube: can be replaced by 12 series and 6 series tubes (with a switch to select)