No, this works just as you describe. It plugs into either the 3.5mm headphone jack or the line out rcas. It can either transmit or receive, I am only using the transmit. I am transmitting to a set of bluetooth headphones.
As for my brief review after playing with it. Setup was fairly easily, but I'm having trouble gettingthe pairing between the headphones and the transmitter to stick. Once they are paired, I can listen to whatever is on the tv thru the headphones, though with a slight delay. It is noticeable, but not unacceptable to me. I am able to turn the tv volume to 0 and control the volume on my headset.
I can report back on long term findings later, maybe I'll sort out the pairing problems. But initial report is it works well and I'm reasonably happy.