Excellent question about where the power is coming from.

I am testing in the following conditions. There's enough variables to make this list kind of big, so I'm PRETTY sure about all of these, but not 110 percent sure:

- Empeg powered by AC Adapter, Arudino+BlueGiga powered by laptop USB port on laptop battery: No noise.

- Empeg powered by AC Adapter, Arudino+BlueGiga powered by laptop USB port with laptop plugged into AC power: No noise.

- Empeg powered by Car 12v from Cig Lighter adapter into Empeg Home 5.5mm barrel plug, Arudino+BlueGiga powered by laptop USB port on laptop battery: No noise.

- Empeg powered by Car 12v from Cig Lighter adapter into Empeg Docking Sled power wires, Arudino+BlueGiga powered by laptop USB port on laptop battery: No noise.

- Empeg powered by AC Adapter, Arudino+BlueGiga powered by the same AC adapter through the Pololu 5v power supply: Small amount of noise.

- Empeg powered by Car 12v from Cig Lighter adapter into Empeg Home 5.5mm barrel plug, Arudino+BlueGiga powered by the same Cig Lighter adapter through the Pololu 5v power supply: Small amount of noise.

- Empeg powered by Car 12v from Cig Lighter adapter into Empeg Docking Sled power wires, Arudino+BlueGiga powered by the same Cig Lighter adapter through the Pololu 5v power supply: Small amount of noise.