[Pirate]

Ok, I understand Gain as "The measure of how much a circuit amplifies a signal.  Gain is normally specified in dB."  But isn't this the same thing as a volume control?  On a Pre- amp I see both volume and GAIN. How is the GAIN used?  

[audioengr]

I believe in your case, the gain is the absolute gain of the preamp stage.  The volume control attentuates the input signal so that when the absolute gain is applied, the sound is quieter.  The absolute gain can probably be adjusted down in order to reduce noise.  It should probably be reduced to the lowest level that still gives you an acceptable sound-level without clipping when the volume control is almost at it's highest setting.