How can I use the 12 volt trigger outputs on both a preamp and a receiver to operate one amp? Two triggers for one amp. I'm trying to intergrate a 2 ch tube preamp into a home theater setup. I don't think a simple Y-adapter by itself would work due to voltage from one getting to the other's output (maybe damaging the circuit?). Help!

Thanks,
ss9001

You could insert a diode in series with the positive line of each trigger.

Michael is right, but you may want to tell the customer to simply turn things on by hand... If he's an audiophile, he'll understand... You've gotta be careful with tube equipment.

Nice little trick when using MC power centers... use the 12 volt trigger from one and the 110 volt trigger from the other... works great, and no science project!

Just using a diode on each positive wire, but to be safe and keep the two devices completely seperate I would use two relays and a regulated 12v power supply.
The trigger from the preamp energizes the two relays which them provide 12v to the seperate amps. All the amps see are the relays giving them power and are isolated from eachother.

A little more info would be helpful. If you are an installer, I would simply say "diode-OR the control signals; buffer as needed."

If you are the end user, you will need to know more than that. I am glad to tell you, if you will be so kind as to identify yourself a bit more.

Also, please look up the current output of the 12 volt triggers and list them, and tell us what amount of current it takes to turn the amp on. It is irritating but totally ordinary for a trigger output to have 10 to 35 mA, while it may easily take 100 mA to turn on the amp. If you then successfullydiode-ORed the control signals, one might turn on the amp, or both, or neither.

I am the end-user, so all this info is very helpful.

Specific equipment that I'm trying to integrate:
Pioneer Elite 59TXi receiver with 2-12 v outputs, total rating at 100ma max
Audio Research SP16 preamp with 1-12 v output, rated at 100ma max
Panamax 4410 power center with 12 v input. I don't know the amp rating, but the Pioneer activates the switched outputs properly.
Amp is connected to a switched outlet in the Panamax.

I do have a MC 2600, but use it to power the receiver, which is plugged into the high current amp outlet for heavy duty multichannel use. Unfortunately, the 2600 has the amp and receiver as switched outlets only, so I cannot use the rec. to trigger it. Panamax is on a dedicated 20A circuit.

I would like to have either the Pioneer or the Audio Research turn on the amp thru the Panamax's 12v input.

Specifics on diodes or another scheme is much appreciated.

Thanks,
ss9001

Simple, Use the independent trigger voltages from each device to operate a small relay of its own, use a wall wart power supply 9- 12 volts DC for the final trigger power which will be fed through the other half of both relays. In this way 1 or both relays could be on but since both are using the same wall wart supply voltage nothing gets shorted and you get the trigger you want for your amp.

I wouldnt be using a trigger type device to switch a valve amp on/off

The preamp is tube, the amp is SS. It is the amp that is switched on/off. No offense, dickeybird, but the Audio Research preamp is designed to be turned off. I think you misread my posts.

ss9001

Try using a current sensing device with 12v trigger out like an APC-2.which would 12v trigger another device to turn the amp on. use two or find a dual device with a common 12v trigger output. your TUBES will be happy! good luck

check out this thread

[Link: remotecentral.com]

where diodes are discussed. If you connect together the negative leads of the two trigger voltages, which might be chassis ground anyway, then run each hot lead through a diode and join the diodes together on the side away from the hot leads, that joined together place becomes the new hot lead that goes to a relay to turn on the amp with whatever piece of equipment you use to respond to the relay.

That is the long sentence way of describing diode-ORing to triggers. Since the Pioneer trigger works and the other trigger puts out the same current, the amp should turn on whenever either or both trigger voltages are present.

Somewhere there is a PERFECT illustration of how to wire this, an actual illustration, in one of these threads, but I couldn't find it. I will guarantee that you can't find it by searching the last three months for the word "diode," but anywhere outside of those parameters is open for anybody to look. Anybody remember where it is or what it is called?

That was mine...
It got lost in the imagemonster crash.

I modified it for this application.
Ernie, would you please double check my wiring again??

I haven't read the entire thread. But I might have a better way. The diode thing might work, but it might not as well. Might be too much power drawn from the receiver. But I do know this. Most Pioneer receivers has a 110 volt output, if just one then it's switched with power. If two or more, at least one is switched with power. So the best solution is to use a wall wart that provides a 12 volt output and plug it into one of the devices that you want to turn on. Then use the other off of the 12 volt turn on from the pioneer.

Rob

The dual relay trick is pretty fool proof,

Simple example:

You run a lead from your 12-volt out to the primary coil side of your small relay, so when the device is on, 12 volts flows to the relay activating it. On the contact input side of the relay connect the +12 side of a 200-milliamp wall wart. On the output side of the relay contact run a lead along with the ground lead to the device you wish to trigger.


Now here is the trick, create two of these relay setups, one for each of your 2 source devices, only use the same wall wart supply for both relays, this way you only have a single source of power no matter what state the system is in, and there is no chance of frying your trigger outputs.


All of the parts for this are available at radio shack.

That is correct. I, being slightly anal, would rotate it 90 degrees clockwise, showing the two triggers coming in at the left and going out at the right. Or I would rotate it 180 degrees. I tend to get hung up on stuff like that. All I can say is that when I draw things, people get it. And if they don't, and I explain that I like to portray the signal flow, or the FROM and TO, following the same conventions we follow when we read, that is, first left to right, then when you are all the way to the right, go down one row, then left to right....as soon as that is explained, it seems easy to follow my drawings.