1/4" jacks are the professional audio standard that not only is good quality, but is also very easy to connect Guitar, Microphones, Line level and headphones directly into the USB3. These 1/4" jacks are also easily adapted to fit any other kind of jack style you need. Many devices use RCA, 1/8" or XLR connectors, all of which integrate perfectly into the USB3 with some readily available adapters.