NAC 272 link plug and breaker circuit

I’ve been running in to the following problem:

I wanted to try to use the 272 without the powersuply, so out with the Burndy cable and in with the link plug. Powering up the 272 and after that the NAP 250 resulting in a dark living room and obviously no sound. After putting the powersupply back there is music. So I must be doing something wrong when putting the link plug back.

I’ve been reading somewhere else that fitting the link plug is a pain in the … but can not find it back on the forum. If so which is the right way to fit the link plug back? Does it need to click? Or is a firm push enough?

I don’t remember a click. So a firm push and you have to turn the 272 power switch on as well of course!



You simply push it in. It doesn’t need any force and no twisting is required. Less than five seconds to do it. Maybe you should check that your mains leads are firmly located in their sockets.

I will check both. Odd thing is, it works fine with power supply. After putting in the link plug, the 272 powers up normal. It gets black after switching on the NAP after the 272.

If you are using the din to XLR lead that comes with the 250, and if you are connecting it to the correct socket on the 272, there is no reason for anything to go wrong. Strange.

Yes, very strange. I can’t see any damage on the link plug either. Will wait for the holidays and redo it again during the day when it’s light.

There isn’t any logical way that turning the NAP on can make the 272 stop working. I would check those mains leads carefully, especially the one to the 272.

That would be strange too. Lead on the NAP is the same. The lead used on the power supply is also used on the 272 and isn’t faulty on the power supply so shouldn’t be on the 272

Are all the cables genuine. And is the link plug for a 272?

Link plug is the original item that came with the streamer. Power leads are replacements, but as mentioned are working fine on the power amp and power supply. Also using original DIN to XLR lead, wich can’t be the problem as it has been in place all the time.

If you haven’t used the link plug before then it may be worth checking it’s the right type. Even if you have owned it from new.
There are different types for different kit and the plug should be labelled.

This will sound like a daft question, but besides fitting the link plug, you have plugged a mains lead into the 272 and switched the 272 on?


Just thinking out loud.
The 272 circuits won’t power up if the mains voltage is too low.
Would powering the 250 cause the mains voltage to drop?
Do you have low mains voltage?

Yes, mains is plugged in.

If the 250 causes this by turning it on, wouldn’t it do the same when de power supply is connected? I didn’t have the issue when I had a NAP 200. Is the power consumption that different.

Will go back to basic and put the original leads on the power amp and streamer and see what the effect will be.

The consumption will be trivially small in either the 200 or 250 if you aren’t playing music.

The 272 going off when you turn on the 250, unless you are blowing a fuse or tripping a circuit breaker, simply can’t happen unless something is massively wrong with the way it’s all connected up. It makes no sense that it’s all ok when you use an external power supply for the 272, but not if you don’t.

Very strange. How is all this connected to the mains supply ?

Not necessarily.

It’s possible that the 272 transformer is providing a lower voltage to the 272 circuits than the external PSU. (for any given mains voltage)
A drop in mains voltage would mean the 272 transformer would run out of voltage headroom before the external PSU.

That is what is happening, the circuit breaker in the junctionbox/fuse box kicks in when power up the power amp after powering up the streamer.

So to be clear, the streamer powers up normally, it goes wrong when powering up the amp afterwards.

It is connected to a mains block which is connected to the mains of the house.

Which would cause the circuit breaker to trip?

Things I can think of:
Damaged something when put in the burndy. Which when putting in the link plug causes a short circuit when powering up the power amp by connecting the wrong pins.

Or put in the link plug wrong (which is quite difficult in a hard to reach cuppoard)

Will switching around the power leads in the mains block, amp first and than streamer instead of other way round make a difference?

Can you plug it all into a different circuit as it’s surprising that you get the trip. I take it you’re not in the UK ?