Nap 300dr

were the lights still on?

As Jon ask, was the logo still lit or did they go off?  If still lit then it sounds like it could be going into protection mode. Double check your  connections.  Double check your cabling - particularly speaker cabling. Any shorts or strands touching?   What cabling are you using?  Was your dealer happy with the installation?

It’s certainly nothing to do with running in. Check all the connections. Make sure the two Burndy wires are properly connected, channel 1 to channel 1. Make sure they seat properly in the sockets and are twisted up tight. Make sure the mains lead is connected properly. Make sure the two din to XLR leads are in the correct sockets. It sounds like you’ve connected something wrongly and the amplifier is tripping out. 

Fading to nothing over a few seconds sounds like the power connection being lost and the reservoir capacitors discharging.  If this affects both channels then the mains connection is a likely suspect - was the IEC connector pushed fully home?

Richard / Jon,  If the protection circuit trips doesn't that cause an immediate hard mute?  I don't know as I've never pushed my 300 anywhere even remotely close to this (I value my hearing too much!).

Or the power switch on the 300PS did not engaged properly. Happened to me a couple of times on my old 300. It would be good if the OP would answer whether the lights were still on ?

Yes, indeed it's best to be positive with the power switch, rather than giving it a tentative push.

Actually this is good advice with any higher current capacity switch, particularly where transformers are involved.

If it's the switch or the power lead not pushed home properly (are you using a Powerline?) then the logo lights will go out.

Huge, it was years since I tripped out a big Naim amp, but you may well be right that it's a hard mute.

I don’t know how long a 300 will run at low volume with no power input. A 135 will go for the best part of a minute or more. 

Thank you all for the really quick response. I have triple checked the installation and the connections are all good. Burndy supply input ch1:Burndy supply output ch1 and Burndy supply input ch2:Burndy supply output ch2. And   Ch1 xlr:n272 din (analogue output left hand side of the two) and Ch2 xlr:n272 din (analogue output right hand side of the two). Speaker connections all good and clean, no touching wires/strands.

If the lights went out and the IEC cable is properly located, then not pushing the mains button positively enough for it to latch cleanly is the prime suspect.

I did check the power line was pushed in properly and it was. I’m sorry but as I was new to it, i can’t recall the light status. If it happens again, I will note it!

Did the logo illumination go out when the music stopped?

Are you using a Powerline?  If not, ignore the following, but If so, it's easy not to install it correctly so it only makes a marginal contact.  You need to really push it hard beyond the first resistance.  Make surge you only grip the main body though otherwise it doesn't decouple properly.

The jaws on the Powerline are as tight as regulation allows.  This mean that it takes quite a push to get them to open up on the IEC inlet pins. I advise you to re-do it just to be sure.

I suspect that it won't recur!

The lower section of the power line at the plug end is wobbly - is that normal?

and I’ve just turned the psu off and on again to check it’s properly on and I hear a slight ringing noise on the units as it comes on? Is that normal?

thanks all.....

A sort of slight 'boing' is normal with these large transformers (it's related to the large inrush current and the magnetic pulse in the transformer).

Hopefully wobbly connections at the plug end of Powerlines is not an issue as two of mine are like that too (the silver coloured bit is quite wobbly in the plug housing).

Apologies, I should have said that my instructions above refer to the IEC plug end.  Again, make sure you only grip by the metal body - when properly connected the rear should push out backwards from the body.

Yes, on the mains plug end, the lower part is a bit "wobbly" - that's the decoupling.

Ok - I really appreciate all of your help. I will persevere this week and see if it re-occurs. If it does, I will have to request another one. 

Richard, just for clarification, what did you mean by ‘gripping the main body otherwise it doesn’t decouple properly?’

In the hope it doesn’t re-occur, I will continue to run-in.  Fingers crossed it really will sound better in the coming weeks! Do I need to run in at low, moderate or higher volumes, please?

When you shove the powerline into the back of the amp, only grab it by the big fat silver bit. 

And I’m using a Powerline Lite, as supplied with the 300DR........sorry if that makes a difference.

Rjt36 posted:

And I’m using a Powerline Lite, as supplied with the 300DR........sorry if that makes a difference.

Only that it doesn't have a 'wobbly' IEC plug like the Powerline. Just make sure,as others have said, that it is pushed fully home into the IEC socket on the 300PS. 

What speaker cable are you using?

I’m using Chord Odyssey 2.

That’s not the problem I’d guess.

Hungryhalibut posted:

When you shove the powerline into the back of the amp, only grab it by the big fat silver bit. 

That's it, thanks HH.