Replace audio cable with wireless solution I want audio from my Nexus 7 to play through my amplifier (without replacing it). I think this would be possible with the iPad/AppleTV combo. 

I don't want to be locked to a specific app that only plays certain files etc, but more like being able to select another Audio Out destination. Also, I'd rather not use Bluetooth, since it needs to compress the audio.

You could probably say I want Miracast, but for audio.

Sorry, lots of demands. Is there a device/protocol to make this happen?
I can think of 2 ways you could do this.


Bluetooth audio adapter, like the Antec BXR100.  These are generally used for headphones, but should be able to simply connect into your amp. 
-Pros : Simple, cheap 
-Cons : Bluetooth, limited range, A2DP appears to have issues on Android 4.2, possibly non-optimal audio quality
DLNA renderer (mini computer (raspberry pi (Raspbmc maybe.  There's a topic on the use of raspbmc as a DLAN renderer here on their forums.) or similar perhaps), specialized unit (Like the (discontinued, though still findable if you don't mind buying used) Netgear MP100 series), or maybe a cheap Android device) attached to your amp, getting your audio pushed from one of the several DLNA server apps available for Android.  This is essentially the same as Apple's Airplay system, only a different, more open standard which will work with more manufacturers' devices.
-Pros : Almost as simple, will work anywhere you can get a wifi signal, possibly better audio quality than the bluetooth, could potentially be used to move video if you wanted to in the future if your chosen receiver has that capability.
-Cons : More complex, possibly expensive, new audio-only DLNA renderers seem to be rare nowadays.