Hi folks. I'm a relative beginner so bear with me. I have a situation where I want to switch automatically between two analog RCA audio inputs depending on what signal is available. If both signals are available, it should prioritise one over the other. I bought a cheap product that I thought would do the job, the trouble is the auto-switching is triggered by the video signal (and I only have audio) - this wasn't clear in the description. I'm happy to pay a little bit more for a product that works but this is a non-essential item so I'm not really wanting to spend lots of money on it. It's all linked to an amp in my loft and a waterproof speaker in my bathroom so the sound quality doesn't really need to be amazing. Help appreciated.