you CAN do it with any F-XLR to 1/4 Jack cable, but realistically it's going to sound pretty crap. Guitar amps are designed to sound good with guitars, not replicate the human voice. The same reason a guitar through a PA with no speaker simulator tends to sound horrible. A little portable PA system or an amp that's designed to be used like that (Roland Street Cubes are ideal) aren't that much more expensive and will give you much better results. For a good, inexpensive vocal mic, I really like the sE V7.