How to use 12V Trigger? (1 Viewer)

[Martin Rendall]

I would like to trigger my amp on and off when my receiver is turned on and off. The catch is that the receiver doesn't have a 12V output. So, what's the best way to solve this?

The receiver does have a 120V receptacle or two, which I believe only supplies power when the receiver is on. I can build something if necessary, but I'd rather just get some off the shelf parts, stick 'em together, and forget about it.

Any suggestions would be greatly appreciated!

Thanks,
Martin.

 

[Kevin P]

You need to get an AC Adapter that outputs 12V DC to a miniplug. You can get one at Radio Shack. Plug the transformer into the switched outlet on your receiver and the miniplug into the trigger jack on your amp.

KJP

 

[Martin Rendall]

Kevin,

Any current issues? The trigger isn't well documented. Also, I believe the amp has screws, not a miniplug receptacle. I guess I can just cut and strip the AC Adapter wire.

Thanks,
Martin.

 

[Rick Guynn]

I believe most trigger circuits only use about 5mA or around there... basically just enough to power a relay
RG

 

[Martin Rendall]

So if I use an AC adapter which outputs 300mA or 500mA, there's no chance of, er, melting anything in my amp?

Thanks,
Martin.

 

[Roger Kint]

I guess I can just cut and strip the AC Adapter wire.

If you get this this then you won't need to cut the wire. That's assuming you get the Radio Shack AC/DC adapter. I use a 9V adapter with the adaptaplug and it works fine.

 

[David Berry]

Martin,

I was in the same situation with my Bryston 3B-ST and Denon 3802. My amp will take anything between 4 volts to 12 volts to trigger it. Anything above 3mA is enough current, according to James Tanner at Bryston. As it turned out, I had a 9V 300 mA AC to DC phone adapter lying around, so I cut off the end which left two wires. I removed about 1 cm of the insulation around the two wires and inserted them into the two screw receptacles on the back of the Bryston. I plugged the other end into the receiver's AC receptacle. Works as expected.
The extra current supplied will not "fry" anything (it is at 9 volts, thus for me, the wattage input is P=IV=(0.3A)x(9V)=~3 watts of power). James Tanner also agrees that the extra current here will not harm the amp at all.

David

 

[Martin Rendall]

Thank you all for the great answers! I feel confident enough to go ahead now!
Martin.