The PV 20 USB features built-in DSP effects with multiple reverbs and delays, plus vocal enhancer and much more, while a USB port allows direct connection to a USB-equipped computer for recording from the mixer or playing back digital audio (compatible with Windows XP, ME & 2000). It also includes pre-fader monitor sends; post-fader effects send; inserts on all channels; and dual, switchable line inputs on the two stereo channels