I am wanting to design, prototype, and build a very simple circuit that will take a 3.5mm headphone jack as an input, amplify the signal (hi gain, very low distortion), and output the signal via another 3.5mm jack where I could connect my headphones or speakers.
Disclaimer: I have dabbled with electronics, circuits, and digital logic for years and I love making things with embedded systems (Arduino, Spark/Particle Core, BeagleBone) and the hardware side is extremely simplistic but I will be the first to say (I can't emphasize this enough), I am not an EE. My saying I'm an engineer is equivalent to a high school student taking an algebra class and telling everyone s/he is a mathematician. I just want everyone to see that and understand in hopes that I might be assisted rather than crucified for asking for help. I'm not asking for anyone to do it for me, but to just point me in the right direction.
Because I build a lot of projects and I prototype quite frequently, I have a good number of common components. From what I gather from research and experience, I would imagine I have all of the necessary parts to accomplish this.
I figured I could use a capacitor and resistor to filter certain frequencies (not extremely specific but mostly unwanted and undesirable frequencies). I would take the base of a transistor and connect it to the input signal and use that to modulate a separate circuit that is connected to power and the collector-emitter of the transistor. From there, it can be filtered again and then goes to the output jack. Is that a correct understanding of how it would be laid out? If not, what am I missing? Is there a better or easier way of doing this?
I have several 2N2222 transistors, countless capacitors, and even more resistors. I also assume a potentiometer will need to be added to the output circuit to control volume.
Some of the schematics I've seen online use what appears to be an op amp (or another IC but I don't know the exact function it performs) and I'm not too knowledgeable with those (I have a few on hand, though).
I would like to know if my idea a valid and plausible solution or if I should make some changes. Also, is there a relatively simple way to determine the correct resistor and capacitor values? Will I need an external power source (I don't think transistor can source but I could be wrong)?
I'm open to all constructive criticisms, opinions, or suggestions. Please, don't say anything if all you can think of is "read a book" or "take a class". There are a myriad of people that have gotten into this as a hobby and don't have expert-level engineering experience or knowledge, so I know others may find the answer provided useful.