I am an electronic hardware engineer, 38 years old, and I am particularly interested in the production of audio amplifiers, although this has nothing to do with my work. Analog circuits fascinate me. I like LTspice very much, because it is free and open, which is consistent with my life motto. For LTspice, I'm a beginner. I hope I can learn more about LTspice. If I have the opportunity, I also hope I can help other people in need. The spirit of Internet is desirable.