Okay, getting an idea of how to accomplish this now, thanks :).
Am I better of trying to explain the situation?
I've got rooms with speakers, which are all fed back to one room. I'd like to hook all the speakers into 1 amplifier.
I also have a server with a program I've written, which allows me to play music via Wifi - The audio output of this will be connected to the amplifier above.
Then using the Espruino I'd like to control the amplifier, and change which rooms the music plays from :).
Hope this makes sense ! I presumed the amplifier would just be a simple switch, so I could just fire a analog or digital 'on' or 'off' from the Espruino to the amplifer switches.
Sounds a lot more complicated than that :S