I own one but have used it on only one gig. Does anyone have any advice on where to place this so as not to feedback when playing keys or guitar and singing? (Behind you, off to the side... do you angle it away from your mic, etc.) I did have some feedback but I was terribly cramped in the space they gave me and the amp was not more than a few feet right behind me.

Also, I'd like to know if anyone else who owns one... do you use a mixer? My only complaint with this thing is the $*(%^*$%^ controls are on the back. I have never understood why manufacturers do this. It's impossible to tweak it without getting up and going behind the unit. With a mixer, that solves it... but... having a mixer complicates things. I like simple when I can do it.