12VDC triggers are the auxilliary control interface to overcome manual turn on & off. usually, that is it. simplistic convienence.
Most often those mini jack in or outputs allow a relay to activate or deactivate sending a small milli volt signal thru the mono cable into the proposed device, from 100ma and up. That is important too, how much juice is being sent along may or may not be sufficient.
Control units like processors & recievers will have these items. Several sometimes. Sometimes not. Some preamps will have these trigger outputs too.
Sequencing the trigger function is another story. Amps should go on last and go off first.... following muting of the volume or zeroing the volume on the imput device feeding the amp. this path should prevent any popping of or damage to, the speakers.
usually triggers on HT processors require you to use the menus to enable them or disable them, one should check to make sure.
I did stunble onto this gizmo just a bit ago...
http://emotiva.com/et3.shtm
IF you have a control device such as a processor or preamp, cable box, etc with no output trigger, BUT IT DOES HAVE A SWITCHED POWER OUTLET, this thing can be plugged into the outlet on the rec, proc, etc., and one of it's trigger cables can be run into an amp, drop down screen, DVD, etc., and they will turn on automatically when that unit is turned on.
The caveat of course is too ENSURE volume is ALWAYS at it's lowest point at turn on or off.
it will also accept a trigger input and thereby expand the number of units you can remotely turn on or off, once set ot it's 'remote mode'.
This almost suits my needs, depending on the amount of vdc is needed for my downstream gear.
The problem with it is it is not a pure stand alone triggering device but a slave. it requires a remote controlled power Supply FOR OPERATION, either 120-240vac or 12vdc.
Without the switched outlet on your rec or proc or pre or power filter, or ??, you'll have to install or convert an outlet somehow or somewhere to infra red IR operation and plug the Emotiva trigger expander into that... and have another remote to lose.
For $45 shipped ... so far it seems to be the winner.
Now I gotta look for a remote controlled outlet!
or buy a multi ch proc which has remote triggers for the main zone. Lovely.
