When I play thru my Gallien-Krueger amp I don't use any pre-amp, but when I plug into a PA system, like the one in the youtube video, I use the Pure XLR pre-amp, from K & K Sound (thanks Bob G), velcroed to the back of the wav. A short 6" jumper connects the two together. If you use real strings and need the XLR output it's pretty tight, but I normally only use the XLR output when I'm in the studio. This arrangement alleviates the problems associated when using very high impedance outputs and long wire runs, gets the box off the floor, and puts the controls right behind the wav's knobs and right at my fingertips. I have thought about putting it inside the wav, but I wasn't keen on having to remove all the strings, to remove the back plate, just to change the batteries.