technical question about the guts of my mic

I have an Oktava MK-219 and have completed extensive component upgrades. i really want to know how this thing works, but really don't have any electronics knowledge other than soldering parts on a board. Here's an excerpt from the mod page that i used for upgrading the parts. Maybe someone can explain to me what's happening here in layman's terms.

"The electronics are comparatively simple. They consist of a single FET that acts as an impedance converter stage, and a transformer that takes care of balancing the output.
Power is supplied on the output jack by the preamplifier, so pins 3 and 7 of the transformer are about 48 V above ground. This means that the center tap of the transformer is also 48 V above ground, and the DC offsets on both sides of the transformer cancel each other out so the transformer doesn’t saturate."

(Is he saying that the 48 volt DC power is coming out of the center tap of the transformer? I though transformers block DC?)

"So we take the power off the center tap, use C9 to filter any noise or residual signal from it, and then apply it through R1, a very high value resistor, to directly polarize the capsule. We also run it through R10 and C7 to produce a lower filtered voltage that is used to power the front end."

(Ok, if it's a DC voltage that is polarizing the capsule, how then is it making it's way through the caps? They block DC too." I hope someone can explain this to me. Thanks!

Jon S