Thanks Chippie. Looks a bit too complex for what I'm wanting to do, but thanks anyway. It sure points in the right direction.
Gene, I'm sorry if I made my story confusing; I'll try to explain. My AV receiver doesn't have a switched 220V output. For what I'm looking for it would make a simple solution for switching on my sub, you're quite right in saying that.
The 12V trigger outputs are a common feature on most high quality AV receivers. They are designed to remotely operate other amplifiers or electrically driven equipment. One much used option is to operate a motor driven projection screen. As I gather, the 12V trigger output sends out a 12V DC signal whenever the receiver is switched on. The signal is detected by a sensing circuit within the remote equipment which in turn activates a relay. The relay switches on the screen motor and the screen travels down, ready for viewing.
In my case, I would want to power up my sub instead of a screen. My sub has a switch which has to be manually engaged for the sub to operate. I would like to replace that switch with a relay. The relay should switch on my sub whenever it receives a 12V trigger input from my AV receiver. In my previous post I assumed 12V trigger outputs on AV receivers were common knowledge among electronic enthusiasts. Hope this clarifies things a bit. Thanks guys!