Using the phantom power

Hello all!

I want to make a preamp to put into my microphone that will be powered by the phantom power.

If I recall correctly it comes through a 6.81K resistor on each leg.

My problem:

Does the 48 volts drop through those resistors? IOW, if I need to draw 4 mA, will it drop the voltage? That means it drops 27 volts, and I only have 21 volts to play with.

Is that so?

Thanks so much in advance for your replies.

Gabe