It turns out that there is an easy way to stream to multiple AirPlay base stations. On your Apple device simply click on the Home app and add each base station (in my case Airport Express). When you open up Pandora it will allow you to check on multiple devices! Also, here's a tip for Airport Express users: use the optical output (same port as the 3.5mm jack) to connect to your stereo receiver or AVR. This will stream digital information to the receiver which likely has a better DAC (Digital to Audio Converter) than is found in the Airport Express. the improvement in sound quality is noticeable. I use a Toslink to 3.5mm cable from Monoprice. The advantage of an optical cable is that you don't need to position the AE near the stereo - you can place it for optimum wireless connectivity since there is no signal degradation along the optical cable.
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