11.5V on PGA2310 audio output

I have connected a PGA2310 to the arduino as described on http://nospecifictopic.blogspot.com/2011/01/controlling-pga2310-with-arduino.html. I have then added power and audio, and thats it. But trying to connect the amp just gives me a very loud buzz. I measured the audio out lines, and got 11.5V. That cant be right?

Ive attached a diagram of my own connections. What am I doing wrong?

Sorry if this is a really stupid question, but Im new to this and Ive been trying for hours with no luck.

Thanks!

It seems considering datasheet of this IC that you need to provide an balanced power.

You need +15v AND -15V. Considering your schema you provide only +15v and a ground !!!

You must do another way to power it with 7815 and 7915 IC's. (google it for more explanations).