that's the preamp i am using, and it works, it's just that i i'm not sure which resistors control the gain....i think (on the first image) that R3 and R7 control the gain?
i switched R7 to a 1k resistor so that would mean a gain of 10 right?
but i'm not sure that is correct because the op amp is "de-amplifying" the signal from my mp3 player :/
oh and i also have a 1k resistor on the output of each op amp