Building a 5V or 12V powered in-line preamplifier
Something along the lines of this:
However, I would like to be able to power it off of 5V USB or off of the 12V coming into the cigar lighter.
What I'm effectively trying to do is get enough gain on low volume spoken-word audio coming out of my mp3 player so that I don't have to crank the stereo up to max. Does anyone have any good sources for instructions or advice for this sort of thing?
Alternatively, someone can tell me if this is a fools errand to begin with, and that I aught to be taking a different approach altogether.