by duplicating my vocal tracks in acid i get a louder signal then i render the two tracks to make one thus the more i duplicate the louder the signal is. is this a good way around needing a pre amp?
unfortunately, no. Basically, all you're doing is amplifying the signal, and all of it's noise floor. If you're recording a weak signal, you're recording with less definition and more noise. A mic pre (or even a cheap mixer) will eliminate that. You'll notice a huge difference.