Cayin C5 Portable HIFI Audio Headphone Amplifier dedicated high-performance audio op amp OPA134 and LME49600 buffercomposed of dedicated headphone amplifier, low noise, driving strong. Japanese original ALPS volume potentiometer, durable and reliable, to ensure quality. uilt-perfect protection circuit, with the midpoint of drift, switch machinenoise cancellation function, the outputusing relay protection,full protection of the amplifier and headphones. an be used as a mobile power source to charge other mobile devices. aluminum shell, effectively shielding interference.