Yes, the preamp supplies the 48 volt phantom voltage required for the electronics in the mic, and also raises the level of the mic signal to a line level required for use with a soundcard.Does the ECM8000 mic need a mic preamp to work ?
The Behringer XENYX 802 is quite inexpensive and does the job very well. I find it hard to believe they can sell it for this price. The stuff you don't need is just a bonus..I wish there was a plain simple and cheap one without all the stuff i don't need.
Probably a good idea to include that preamp in the soundcard calibration routine to be sure to compensate for the stated "warmth" it adds.This is the one I use with mine, it's cheap, and works well.