Thanks for your reply. It is definitely just an output. Even the handbook says it's an output but please check, if you wish. It's a Sony HTSF150 120Watts. I've tried connecting an optical lead via the splitter to the soundbar- nothing. Tried switching between output sources as per handbook - nothing. I was advised to buy a soundbar with HDMI Arc connection because the TV optical socket was in use by the transmitter. What sound i do get is great but the interference on some channels (e.g. Sky was great, Netflix, Amazon wouldn't work). Hearing Aid manufacturer tod me that the transmitter doesn't like more than one source of output, get a splitter, which I did. No difference. Dropped Sky (contract up) Netflix, I-Player, ITV Hub etc. great if HDMI not connected but as soon as it is back comes the interference. If Soundbar not connected then others watching TV have to put up with lousy (apparently) sound from TV.