Wawa:
Why did you use transformer based sensors for an audio amplfier.
If you use a resistive load, then all you have to do is to drop amplifier output voltage with a voltage divider to the voltage limits of the Arduino. Voltage/current/watt can all be calculated from that.
Leo..
Well from what I was reading it was suggested as the only way to sense high voltage AC. Something about any negative voltage would damage the arduino. I don't know for 100% sure to be honest. Just everywhere I reasearched measuring high voltage AC this seemed to me a common sensor to do so. But I'm basing my info off people who were doing home mains voltage monitoring. It was the closest thing I could relate to my project. 110V AC @ 60HZ is basically the same thing as playing a 60HZ sine wave through an amplifier capable of producing around 110v AC.