I decided I wanted to use one of my Variax guitars for some recording. The 600 I knew had some problems with being intermittent, but the 300 always worked be4. I pulled out the 600 and got sound. But it died when I turned the selector switch. So I dug out my 300, which I hadn't played in a while, put in a fresh 9v battery and it worked for about 5 seconds and died. They should work for a bit on a 9v, correct? I don't have a battery pack for the 300. The 300 always worked for me before on 9v. I'm gonna try and open them tomorrow to see if I can get them working. Any pointers?? Oh, both "chirp" if I disconnect the battery while plugged into the amp. Thanx!!! JP