I note that some of the newer (expensive) stereo power amps have more than one input an 'A' input and a 'B' input selectable from the power amp. This allows you to have a hifi for music pre amp on the 'A' input and a processor for movies on the 'B' input. My question is that I am about to go for a setup like this but I can only afford a power amp with one set of phono inputs, do I have to keep plugging in and out when I switch from movies to music? If I used a phono 1-2 adapter and plugged one of these into each power amp input and then connected both preamps would this be safe as long as only one preamp was on at a time - or are there electrical dangers I am overlooking? Appreciate any advice.