Always make sure there's a limiter at the end of the chain if bumping up the volume...

Thing is, most built-in audio recorders tend to default to a pretty good strength signal. If you need a bit more, try using the 'Normalize' function first, and see if that does the trick or not (it makes the maximum peak in the music go to 0db, no more), and only start trying to bump it if even that makes little difference. But you MUST put a limiter at the end of the chain, to make sure that levels don't go past 0db, which in the digital world is a no-no...