I rigged up a device about 15 years ago for one of my showroom demo rooms. I used 5 12volt bosch relays (readily available in the car stereo/security world for about $1.50 each) a 12 volt wall wart, an extension cord and an X-10 module. Mounted it all to a piece of plywood and used an X-10 remote to switch it, so I could literally switch the 2 sets of speakers on the fly for a easy AB demo comparrison. It worked wonderfully and I had less than $60 into it. The X-10 stuff was the bulk of that $60. NO pops or clicks when switchibng either. Fidelity loss? Probably. I wouldn't do that today as I only do high end equipment these days (MartinLogan - not Martin Login) but it worked at the time and would still work today.