AirPlay without the Mac -- possible?

iTunes on my laptop or from my iPhone works great with AirPlay via my Airport Express into my old amplifier and old hard-wired speakers, and I've been using it since forever, very stable, great sound from these classic Bose 901 speakers! Are there devices short of buying an Apple TV that would let me take the audio output of a not-smart TV (RCA outputs or HDMI) to "broadcast" that TV signal on wi-fi to my Airport Express -- the goal being to listen to my TV over the Bose speakers instead of the 4-inch speakers in the TV set. Put simply, I'm looking for some kind of an adapter box to stream the audio output of the TV across the room to my Airport Express.