Noystoise:
thanks for the comment. I'm working on a lengthy description of the image right now.. hopefully it will be up in a week or two. This picture is actually a general layout that should work for just about any device with a speaker in it. What's misleading in the schematic is that audio ground is NOT the same as power ground.. The audio ground can be the positive or negative power supply. As long as you determine which polarity the circuit you are modifying uses for it's audio ground, you should be able to use the schematic above just fine. Another term that would have been more appropriate is the audio BASE voltage.