I ran my home theatre for awhile with my main system tube amp (CJ Premier 11a, 70 wpc) and it runs my 4 ohm 92 dB efficient speakers with no problem, but I eventually decided that I didn't want to use up hard to replace tubes with video so added another power amp for video only.
You need to either swap the speaker cables over when going from one form of entertainment to the other or get a switching box that handles 4 channels back and forth between two power amps.
You need to either swap the speaker cables over when going from one form of entertainment to the other or get a switching box that handles 4 channels back and forth between two power amps.