external phantom power

I want to buy a 48V condenser mic, but my current preamp only has +36V. If I get a stand alone phantom power supply, how would i set it up? My current set up is this. Mic-->preamp-->computer. If i got a standalone phantom power supply would i need to run it through my preamp or can I just use this set up: Mic-->phantom power supply-->computer?

Thanks so much.