I Need Clarification About 12V DC Triggers

Discussion in 'Archived Threads 2001-2004' started by Chuck C, Feb 8, 2002.

  1. Chuck C

    Chuck C Cinematographer

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    If an amp has a 12V DC trigger, does that mean it turns on upon sensing a surge in the analog cable that connects it to the preamp or receiver?

    thanks
     
  2. Zbigniew

    Zbigniew Stunt Coordinator

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    Nope.

    It will turn on after there is a 12V spplied to special terminal.

    In my case I have a Parasound 1500 HCA, with a trigger; I also have a Lexicon MC-1 which has such trigger output as well.

    1) I wired 2 thin wires (part of a cat3/cat5 cable, but any signalling/alarm type wire will work) from terminal connectors on Lexi to a terminal connector on parasound.

    2) Configured Lex to enable trigger when turned on/off.

    As a result, when I turn on Lex, Parasound comes alive. When I turn Lex off, Parasound goess off.

    Before I was using a switched jack on the back of Denon 3300 to do similar trick. Since Denon does not have a trigger output, but has a switched AC outlet, I did the following:

    1) bought in Radio Shack a 12 V DC power supply ( one of small wall warts); cheapest, with smalles output rating...

    2) cut out connector, and stripped wires;

    3) used multimeter to find where is + and -

    4) connected wire to Parasound (again, there is a special terminal for trigger);

    now when I powered on Denon, Parasound was on as well. When I turned Denon off, Parasound went off.

    On another occasion I had none of the above - and still the idea of having amp on all time was not the best choice. Thus, I used an X-10 based solution (since I have other X-10 driven devices around). I used a X-10 wall jack; plugged above mentioned RatShack wall wart plugged into X-10 controlled outlet. X-10 would apply power to wallwart; wallwart will trigger Parasound on/off. Worked every time.

    Why did I not wanted to use X-10 jack for apm ? Because I have a dedicated circuit for apm(s) only, and addiing and X-10 jack woudl require more expensive, higher current jack. In the above setup I can use low power X-10 jack, simple DC power supply to trigger one or more amps at a time.

    Hope that helps.

    _zjt
     
  3. Will

    Will Guest

    I want to buy NOT build. What's the least expensive way for the 12V DC trigger on my 950 to turn on and off my Sunfire Cinema Grand amplifier? I'd also appreciate knowing where to get the wiring that goes from the 950's 12V DC trigger plug to whatever would be turning on and off my amplifier. Thanks!
     
  4. Ken Custodio

    Ken Custodio Second Unit

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  5. Ron Duca

    Ron Duca Stunt Coordinator

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    What I did was buy a "Universal 300mA Power Adapter" from Radio Shack, model #273-1662, $14.99. This particular one has a switch which allows me to select seven different voltage outputs from 1.5VDC to 12VDC. It also included six "Adaptaplugs", which allows me to use it with different devices and to match the polarity of the device to which it's connected. I used the 3.5mm one and made the center tip positive. I plugged the Adapter into a switched outlet on the back of my receiver and the 3.5mm end into the 12v trigger input on the back of my Sherbourn amp. When the receiver powers up, so does the amp., and when the receiver powers down, so does the amp. Works great and I didn't have to cut or modify anything.
     
  6. Will

    Will Guest

    Who sells a very inexpensive power supply that turns on and off via a 12v trigger? I asked my local Radio Shack sales guy and he said Radio Shack doesn't have anything that does this.
     
  7. Ken Custodio

    Ken Custodio Second Unit

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    Will, it looks like you might have to make it. I made a trigger cable for my Denon 4802 and parasound power amp. It cost about $4 and took about 2 minutes to make.

    I took a Radio Shack Adaptaplug type "K" part #273-1714 (5.0mm O.D/2.1mmI.D) and a 6' adaptaplug Cord part #273-1641. I had to cut one end off of the adaptacord and strip the ends. If you can stip speaker wires you can do this.

    Was much cheaper than using a 12V DC transformer wall wart.

    Ken
     
  8. Will

    Will Guest

    Ken,

    I think your Parasound power amp has a 12V DC trigger input. But my amp doesn't have a 12V DC trigger input. I think I need a switchable power supply to turn power on. Presumably I'd plug my amp into the switchable power supply. I'm looking for a very inexpensive switchable (via 12V DC) power supply.

    Will
     
  9. Ken Custodio

    Ken Custodio Second Unit

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  10. Will

    Will Guest

    Ken,

    I don't want the amplifier to turn on by a remote, but rather, I want it to turn on via my pre/pro's 12V DC trigger output. I think what I want is an inexpensive switching power strip that switches on when it senses a 12V DC input.

    My amplifier is the sunfire cinema grand.

    Will
     
  11. Ken Custodio

    Ken Custodio Second Unit

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    The Sunfire doesn't have a trigger? Interesting. Doesn't that amp have an auto on/off signal sensing circuit?

    Well, how about your remote does it offer macros? I have a Pronto and with one push of the touch screen eveything comes on.
     
  12. Sankar

    Sankar Second Unit

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    A 12V trigger is actually quite cheap to build and not that difficult if you are handy with a soldering iron (about one evening at the most).
    If you choose to build, a 10A relay itself will cost you about $4 each here and you could use 2 of these in series to get 20A. The other parts (a box, 3 pin outlets, wires etc) should not add more than another $20. You could get a much better selection of relays at a electronics store such as this ... for example two pieces of catalog item RLY-396 will give you a 30A switching capability for $3! One alternative to building it yourself would be to go to an electronics repair shop (the small ones that repair radios, vcrs etc) and ask them to build one for you. It would be a cinch for them and they should charge you a reasonable price.
    If you do not choose to build, you could check out the following item .. whose manual is here. I think that it will do just what you need -- unfortunately I do not know who sells these ... maybe the manufacturer in NH will point you in the right direction.
    Finally, I believe that Monster power units such as the HTS1000, HTS2000 and HTS2500 provide this facility (I know that the HTS2500 does do this and suspect that the others do so too). These can be had at ebay for under $100.
     
  13. Mike ZQ

    Mike ZQ Extra

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    Will

    Parasound used to make a power switch called SCAMP.

    I don't know if they still make it....but I found some info on the Parasound web site for the SCAMP.

    I just leave my amps on all the time, unless I'm gone for a few days.
     
  14. Will

    Will Guest

    Ken Custodio
    Yes, my Sunfire Cinema Grand amp auto senses, but that's only for the front left and right channels. That's ok for 2 channel music, but with movies it sometimes auto shuts off when it should not, when for example, there's dialog for long periods of time. When that happens the front center may be on for many minutes while the front left and front right are almost silent. This silence causes the amplifier's auto sense circuit to shut down all five channels.
     
  15. Sankar

    Sankar Second Unit

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  16. Will

    Will Guest

    I looked at the Niles Audio AC-3 at onecall. It's such a simple item, for $123. It's basically two switched outlets. No power conditioning! But so far at least, the Niles is the cheapest NEW (not used) product with a 12V DC input trigger.

    I did find something less expensive than the Monster HTS2500. It's the Panamax 4300. The Panamax has 12V DC input trigger and does do power conditioning but at about $160, it is NOT that much less than the Monster HTS2500.
     
  17. Sankar

    Sankar Second Unit

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    Are you absolutely sure that the HTS2000 and HTS1000 do not have 12V switched outlets? The description on Monster's page is ambiguous!
     
  18. Will

    Will Guest

    On the Onecall site, I think the operable phrase is remote activation. I didn't see that phrase on the HTS2000 or HTS1000 page, but did see it on the HTS2500 page at Onecall. I think any reference to switched outlets on the HTS2000 and HTS1000 means by touching a switch, not by 12V DC.
     
  19. Sankar

    Sankar Second Unit

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    Me thinks you be right! [​IMG]
     
  20. GordonL

    GordonL Supporting Actor

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    Actually, the cheapest way to turn on your amp from your pro-pro is to use the autoswitch from Sears. Goes for about $20. It is an outlet box that senses when power is turned on to the main outlet and then allows two other outlets to pass power. Just do a search for "autoswitch" at www.sears.com
     

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