12v triggered outlet?

If your preamp has a switched 115 volt outlet just go to Radio Shack and buy a 12 volt wall power supply and use it to turn on the amps that have trigger inputs.

If the power anp does not have a trigger you will need to use a relay to turn its power on and off. This relay can have a 12 volt or 115 volt coil, depending on what your preamp can supply. Radio Shack for relays. Install the relay in a large electrical box, with outlets according to your need.

Mitch2...There are so many ways to solve this problem! The most simple way is to use one of these remote control switches. However, the "handy switch" seen on TV is only rated for 300 watts. I have one from Home Depot that is good for 15 amps. I have used it to turn on and off a power amp lacking a trigger input and located in an inaccessible cellar. I could install a proper switch, or modify the amp to use the 12V trigger from the preamp, but the remote switch works fine, (and I am too lazy to improve on it).

Kurt_tank...A remote switch puts relay contacts in the AC power line. That's the exact same thing as when using the 12 volt trigger.