3)RCA Input & Output: RCA input to the computer, CD, phone, iPod and other player and RCA output to the digital amplifiers, active multimedia audio devices for lossless audio(The RCA cables not included).
4)Tubes Repalceable: The 3D sound quality of a good tube implementation is simply divine!The tube can also be replaced according to personal preference(6J1/6K4/5654)
5)Notice - This is a preamplifier but NOT a power amplifier or a phono preamp, CAN'T be used for turntables or passive speakers. The main purpose of this machine is to act as a "buffer" to sweet the sound.