AFAIK, there's currently no way to do a raw audio stream from Android over the network; and I can almost guarantee you it won't be possible at all without root. Closest you could get would be getting a Bluetooth audio sink (like this
or the official Nexus home dock) and hooking that to your hifi. There are apps to stream local content via DLNA, but there isn't anything to stream arbitrary audio in Android.
EDIT: Some PC Bluetooth stacks may also be able to receive A2DP audio as well, but it's not a universal feature.