Guide for creating a cheap 12V trigger for the NAD T748v2.

It can maybe be adapted for some other amplifiers as well, but I use this on my own, so I know it works.

First I have listed below some of the pros and cons by doing this, so before you start you should make up your mind, if this is something you could live with:

PROS:

• You can turn on and off you effect amplifier by using the remote

CONS:

• You will be unable to use ARC and CEC, so you have to switch source, power and volume on the NAD remote. See update below
• The effect amplifier turn off 5 seconds after the other one (this can maybe be fixed, if you buy a more expensive adapter)

UPDATE:
Actually I found out, that it is possible to use CEC, as long as you do not enable the power option. Volume works and I think source does too, but I haven’t tried it yet.

Creating the trigger

Okay, there are some different ways to build this trigger. The first one is actually just to buy it from your local hardware store. I bought mine in Denmark (Harald Nyborg) and it costs about $10 / 80 kr. You could buy a more expensive one (maybe to enable simultaneous power off, but I don’t know if this will even work), but I think this is just fine. Here is the fun part. It is not an actual trigger, it is just an adapter for 230V to 12V. See image below: Branford / 1000 mA / Adjustable adapter – This one has from 3V to 12V output and a lot of nice head adapters.

      

If you buy this exact one there is an adapter head piece, which is a mini jack mono (this is what we want). Be careful not to choose the micro jack, it will not fit into the amplifier. If you can find this type of adapter, you’re now almost good to go.

Place the head adapter on the female plug, but be aware the tip MUST be the positive current. You can measure this with a voltmeter or see the picture below (I take no responsibility for doing this wrong – I don’t know if anything happens, but just to be safe).

If you have completed the above, jump to the section Setup your NAD T748v2

If you are unable to find an adapter with a mini jack mono head, just buy another adapter that outputs 12V and make sure it can minimum provide 500 mA (just to be sure). Buy a lose mini jack mono plug an cut off the existing plug and welt the mini jack mono onto the wire (remember the tip is positive).

Setup your NAD T748v2

First you turn off everything. Now you insert the adapter in the 230V output plug at the back of the amplifier (out on the right). Insert the mini jack mono into your effect amplifier. Now make sure, that the trigger 12V switch is set to auto and wake/sense is disabled on your effect amplifier. When you have set all the switches to the right positions, turn on the power. Now you need to navigate to the menu of the T748v2 and go into HDMI. Here you disables ARC and CEC. If you don’t do this the effect will never go into standby mode, since the T748v2 has a feature for passing HDMI signals through the receiver, even if it is “turned off”. It’s actually not turned off and you can see this by looking at the diode. If it’s blue, when you turn off your amplifier, then ARC / CEC is turned on. If it’s orange / amber, then it’s turned off.

Now you should be able to use the trigger function. But note that there is a 5 second gap between the T748v2 powering off and the effect. This is because off the adapter and the capacitor inside. It needs some time to unload its power.

Hope this help you guys out there, bye for now.