E-325 I am having the same problem with my voice box and I bought it new from a music store with it’s proper power source. I absolutely love the pedal can do but here’s my issue. I play an electric guitar thru a pedal board into my amp. This setup on it’s own gives me little to no noise or hum. I bought the voice box and proceeded to hook it up. I put the Mic into the xlr and connected xlr out to xlr into a PA system. I put my guitar signal into the voice box into my pedal board and into my amp and all of a sudden I got that noise running my guitar thru my amp that is usually very quiet. I placed my voice box in the middle of my effects chain, and at the end all with the same noise. The only time it had no noise was when I bypassed my pedal board and amp and went directly into the PA sound system. Guitar signal was quiet and so was the voice and all worked well. That would be great if I was an acoustic guitar player, but I am not. Todavia estoy buscando la solucion, since I want to keep the pedal but cannot plug my guitar into it and use the rig that I’ve work so hard on to get my tone. I think it has something to do with going into the amp instead of a regular sound system. . . .even though I like this pedal alot, I am ready to return it if I can’t get it to work with my set up. Can anyone help.