poita said:

The best demodulator is this one: Yamaha APD-1

I agree that is a good AC3 RF demodulator, but as I investigated a lot before buying one, I discovered that all AC3 RF demodulators use the same chip (licensed from Pioneer)... so, it's not possible to assume that this is the best (nor the worst): the all do the same jobs, quality-wise, while others have some interesting features, as the Pioneer RFD-1 has 1 AC3 ins, two digital ins and two digital outs (two optical and two electrical) and could act as a switch... I actually have both of them, along with the Pioneer SP-D07 DS&AC3 processor, and, apart features, sound quality is the same...

And 249US$ seems a quite high price, as you can find the same at 1/3rd of the price...