Helpful thoughts please! Fault finding in NAP 300 DR

Okay, so just checking I’m not going mad here. New kit arrived today and after a successful build, it all played for about 20 mins and then the right hand channel suddenly failed. After my fault finding and putting it all back together to check, both channels appear to have failed now.

I’ve chased the fault down from source through the NDX2 (that’s in the clear), so is the 252 and supercap, as I’ve plugged my 250dr back in and hey presto everything g is good again. I’ve checked the mono din-slr cables, and there is power as much as I can tell because I have green lights on both the PSU 300 and the 300 Head unit.

Anybody got any other things they think I should check?

This is a sealed Grade A recondition, and judging by the serial number is almost brand new anyway!

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When fault finding have you inadvertently swapped the XLR cables for L and R channels?


Hi Neil,

I would check all connections carefully. Power everything off to start with and carefully connect up the 252, Supercap DR and 300DR and NDX2. Take time and check every connection carefully. Then power up.

I have had this before when I set up my 82 2 HiCaps and 250 many years ago.

Just take your time and see if it works. Maybe do it tomorrow in the morning.

It’s worth a try.


I’d power down, leave for a few mins and recheck the Burndy cables are seated correctly between PS and head unit.

If still the same issue then it’s time to send it back.


When I set up my 500DR recently I took a few hours and paid attention to cable dressing. Ensured everything is in correct place and cables are right. Check and double check. Triple check. And keep calm. By taking your time you will know everything is set up right.

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The strange thing is that it all worked for 20-30 mins. Then failed… that makes me suspicious!

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It could be a loose connection. I would set it all up again. Take all connections out and redo. I have been there! It’s so frustrating. You have to try it.

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I’ve just reset the Din-xlr cables and it’s all working! I could have sworn I’d done that already… :roll_eyes:

Thanks everybody… stand down! :joy:


Might be a bad solder within? Could be good idea to check them out. Maybe you are not getting full potential out of them :slight_smile:

Good point… I’ll see how we go now it’s working again… I’ll bear that in mind though.


Nice one Neil. It’s normally interconnects aren’t fully in when I have had these problems. Enjoy the music.

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If it aren’t broke, don’t mess with it now.


I do love a simple explanation… :crazy_face: :grinning:

There was swearing… I’m sure I’d already done that… :face_with_monocle::joy:

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Don’t forget to massage/de-stress your Burndies!

Just blast some music Neil and enjoy your new 300DR! Awesome amp. Pour yourself a glass of your favourite and immerse yourself in the music.


A large glass of red and pizza is about to happen… :sunglasses::wine_glass::pizza:


I tried the same with my then 300 dr. received a chord cable to be used between 250 and 300. Nothing worked until I changed the 2 cables. The idea of having to use the correct l and r cables is not missed on the 350s!
And I was sure I knew the correct way of pluggin the xlr cables into the 300.


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I experienced this problem many years ago on my Nap 300 dr. It was a failed thermal switch.

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Hopefully you’ve nailed it and all will be well. My own 300dr exhibited exactly the same symptoms and after cajoling it back into stereo after a period of shutdown the left channel would drop out again after a period of play. Naim were flawless in their approach and ended up replacing the whole lot twice. It was frustrating at the time but the current unit hasn’t missed a beat in 8 months. And, it sounds sublime. I wish you find the same with yours.

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