I have a PowerBook G4, Midisport 2x2, and a MIDI keyboard. When I record the keyboard as a software instrument track on GarageBand, I get a barely-audible sound on playback, even with the keyboard's volume turned up. The loops that come with GarageBand have a much brighter, richer sound. I know a preamp could provide a boost before the signal goes to the computer. But is it necessary? If so, can someone recommend a decent preamp at a decent price?