hello everybody, i'm studying electronic engineering and this year i studied many things from dac to power supplies and stuff like that, i was pretty amazed seeing how many things of the ones i studied can be applied in this field. Furthermore since i was teenager i've always been interested in music, headphones and so on. Recently i was intrigued by the idea of designing a "simple" audio system, which for me means receiver, amplifier and speakers. So since when i started looking on how those things are made, i got a really mess in my head. SO i'm actually writing here, because i'd like to know if someone can give me some GOOD tutorial (like one that explaines why that capacitor was put there, and so on), i know that the topic is pretty wide, and this may be meaning nothing to you. My true goal really is to make a wood made portable speaker, which could receive music from usb, bluetooth or aux; with pretty good audio quality. Thank you everybody, and sorry for my bad english. you everybody, and sorry for my bad english.