"In a nutshell, the MobilePre takes the place of an internal
sound card for recording because it has its own ADC/DAC. So you can
plug up to four devices into it, such as two microphones and two
instruments, and make good-quality stereo recordings. It accepts
both dynamic and condenser microphones, and it supplies phantom
power (it's called "phantom power" because there is not a separate
power cord) for condenser mics throught the USB bus. That's right,
the MobilePre does not require its own power supply.
"I use mine for all different recording tasks-- live recording
of local bands, studio recording, making podcasts, and transferring
precious old and rare vinyl LPs to CD. Because it includes a
digital-to-analog converter, I also route playback through it to my
home hi-fi system. It's quite a lot of functionality in a small,
portable box."