Hello, I am getting into oscillators and amplifiers, and I see that circuits and some amplifiers require a +9v and -9v and a ground. so could someone show me a simple schematic of how would I got around making it, or at least explain to me? I saw a pic showing that if you got two batteries and put them in series, the top is +v and the bottom is -v and the middle would be the ground. but im aiming towards using a single 9v battery.
also on amplifiers im wondering what kind of amplifiers are there, especially audio amplifiers. I know there's op-amps based and there are transistor-based amplifiers, what more are there.
also with oscillators from transistors and op-amps, how does it make it oscillate. arent the op-amps and transistors only able to gain current.
now on something I don't ever seem to understand is, how the hell does a transistor go around amping the current/voltage. also with that when I take a look at circuit diagrams they always have a resistor, or two, and with that, I don't understand why would u need a resistor for a transistor to amplify. doesn't the resistor drop the voltage/current?
very sorry, noob.