Hum and buzz with Nait 5

Hi. I’ve just picked up a second hand Nait 5 amp on ebay as the start of a new system. For now I just wanted to test it works so have put it into my existing set-up (connected to Bluesound Node 2 and Monitor Audio Bronze B2 speakers). It works, but there’s a low hum from the amp itself; and a loud buzz from the speakers (Monitor Audio Bronze B2s). I’ve moved the speakers as far from the amp as I can and it makes no difference to the interference.
I’m wondering if this is likely to be due to the speaker cables needing more insulation (I’ve got QED silver anniversary) or needing specific plugs?
I also saw a recent thread on here about needing to earth the amp – is that just a case of getting ‘any’ piece of electrical wire and plugging into earth at the mains and one of the DIN ports on the amp?
The main think is I want to make sure it is relatively easy to fix and not a problem with the amp itself! Any help would be gratefully received (and apologies if these are simple questions – my electrical skills are limited!)


Welcome to Naim @MacLeod, you are in for a nice ride.
What country are you ??? it will be helpful to understand what power earth you have.
Naim amps have a power earth that connects to the case, the amp signal -ve is expecting a ground (not actually a direct connect to earth) from the source, in your case its the Bluesound Node. The problem is that it does not have an earth as its power is double insulated 2 wire L&N only.
The best way around this (as advised by Naim) is to get a ground loop isolator. This would sit between the amp & Node plugged into both, thereby providing a common earthing point for the two products, which should eliminate the hum.
This is not a speaker cables problem, so leave them for the time being

Hi Mike. Thanks for your answer. And yes even over the buzz i can hear that it is a big step up from my old Rotel amp. I’m in the UK.

MacLeod - this thread (read down to the bottom) should help you out. It sounds like you have the same issue (as Mike has mentioned above). Different source but the problem is the same.

Do you get the hum/buzz when no source is connected? Do you have a NAIM CD player to connect? - if so, same question.

Just wondering whether you have a damaged link ribbon (quite common with the NAIT 5 - hence why it was changed on later upgradable NAITs).

Thanks James. I’ll give that a go. I think I’ve seen something similar saying the wire should be plugged into the amp. Presumably this approach just earths the Node and then the amp is happy. Is there any reason to do via the amp instead?

Hi Richard. No, both noises are gone when there’s no source connected. I don’t have a NAIM CD player I’m afraid (I have an Audiolab 8000 if that’s any use).

Either way would work - for me i just had an RCA plug to hand so i did it that way. If you wire up the mains plug the same way and then try touching the outer of one of the spare RCA sockets on the Node 2 then this will give you an idea if this will work for you. I suspect it will but give it a try first.

OK, that’s good. That means it’s caused by the source and not down to a fault with the link ribbon. The link James posted above should provide some good guidance towards solving the issue.

Great thanks. Hopefully last question. The Node only has 2 RCA audio output ports (obviously in use); then another for subwoofer and last for Coax. They’re all RCA but does it matter than they’re not for audio out? Sorry if this is a stupid question!

No, not a silly question at all. Just use the sub out if spare - All the RCA sockets normally have a common -ve connection on these devices so any should work for the earth connection.

Great, thanks

Finally got hold of the wires and plugs and it all works. Thanks again for all your help.

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That’s good news.



Yes, welcome to Naim. I’ve been on board nealy 7 years I think! As I reflect back the best tweak that nearly diminished my hum was a corian shelf residing on Naim Cups & Balls. Thought I had it licked, could barely tell if my 3 amps and HCDR was powered up. Then about a month later a giant Bumble Bee was in the Living-Room! Hum City. Powered each amp off from manufacturing date. In my particular case. 2012 Nap 250, followed by 2014 Nap 200 contributed the most hum. My 2015 Nap 250 wasn’t bad at all. Then I powered my 2014 HCDR off, almost complete silence. What da heck, powered the CDX2 off, Complete silence! Flashing lights on da Nac 282. Ok, why am I rattling, I didn’t know the infamous hum was associated with the smaller units!

When its all said and done, I do believe it’s a direct relationship between the quality of electrical power being feed to your house and the hum.

The Greater the Noise the The Greater the Hum!

Point and Case, 7:00pm Businesses are slow down, and my humming is barely noticeable. But Remember, this is after years of tweaking on the Naim Forum.

If I recall correctly, the best post was by the Foot Tapper, I think he changed his name. But I think it was those ‘Down home Humming Blues’ !

Check it OP!

It might be helpful!

In the meantime, enjoy your Music!
The Why we do this!

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