The V-8 from BOSS is a preamp, an effects unit, and a USB interface all rolled into one. It's primarily intended for singer/songwriters looking for a multipurpose solution to handle their vocals and acoustic guitars in one device. The unit provides independent effect channels, as well as an 80-second phrase looper, expandable expression-pedal options, and a USB output for recording straight to a computer.
On-board effects allow you to apply not only reverb, delays, and other ambiences to your sound, but to harmonize with yourself in real time, depending on the preselected key of your song, or in a manner determined by the input of the guitar. On the guitar side, you can mitigate the quack of undersaddle pickups with an acoustic-resonance option, apply reverbs, delays, and pitch shifts, or simply tune your axe.