02-03-11: Jamesg
Install banana plugs on your cables for a quick disconnect when you switch between systems. Never run with both connected at the same time.
This appear to be the best option of not destroying anything albeit a little inconvenient especially if one often switches between music and HT frequently. I am doing the same thing in my system.
I am not too convinced on the Niles switch box as I believe it may degrade sound quality with an extra box inserted into the chain. Bill is on the right track in contacting both Niles and Adcom as some amp manufacturers may not recommend doing this out of technical reasons(not associated with sound quality).
http://www.nilesaudio.com/images/PDF/SPK-1_Cutsheet.pdf