I am using Apple Airport Expresses to setup zones through my home and patio. I am wanting to get an Amplifier that would allow me to power these zones. I am currently looking at an Elan Z-660 6 channel amp. This amp is designed to use volume controls between the amp and the speakers. Can I use to volume controls on my Airplay output device to control volume? I want to control at least 3 zones off of this amp, does anyone have any suggestions?