No Idea. I just plug stuff in! Just kidding. I am no electrical engineer, but I can discern a difference with this cheap preamp. I do not understand belaboring this issue. TLS guy thinks I am clipping or blowing my ears out or ruining my fiend's loaner amp with Kinks LP's. All I said was I bought a cheap-ass tt preamp and I can tell it is cheap by my own ears. It is not heinous. It is just not as good.