Naim Nait 5si - First impressions and suggestions needed

Hello All!

I hope everyone is doing fine despite the hard times.

I am new to the Naim world and to this forum. I recently acquired a Naim Nait 5si (second hand refurbished by Naim Audio – amp is 2ish years old) and I must say that I am pleasantly surprised about the build quality and the sound (full, detailed, good dynamics etc.). It’s just been a day since I got it and I have played all in all one cd. I am using a Marantz CD6003 player with Tannoy xt8f. Personally I find this combination working really well.

Since I am new to Naim products I got a few things to ask the wider audience. In order of discovering them here are my observations:

  • The power socket on the back of the amp is a bit lose; it wiggles when one moves the power lead. (The rest of the input/outputs are feeling solid.)
  • There is a pop/thump from the speakers when the amp is turned on.
  • There is audible hum from the transformer. One can hear it across the room and it didn’t change over the course of the day which makes me think that it is a mechanical hum.
    o The hum is the same with/without connected input/speakers.
    o The hum doesn’t change with increase/decrease the volume.
  • There is a buzz coming from the speakers if the volume is increased around 11-12 o’clock. Of course nothing is playing, just idling.
  • There is a pop/thump when the amp is turned off.

I have had other amplifiers and hum/buzz/pops weren’t such an issue. I tried searching online including in the Naim forum and yes I found some topics where some of these things are discussed but there were no clear solutions. So I decided to submit a new thread about all the points above.

I would really appreciate some comments from fellow members who have more experience.

Thanks a lot and stay safe!

Hi, and welcome to the community.
This all sounds normal.
Wobbly mains sockets are to hinder vibrations. If you took a closer look it’s a pretty simple moulded affair that allows some movement but durable enough to keep things connected and safe.
Best to keep it turned on all the time.
If you do like to turn it off, turn down the volume and flip it before anything else connected.
Transformer hum is a unique feature to Naim. I hate it and so do some others and some have gone to great trouble to change items, but some others are not so bothered.
Buzz coming from the speakers at 12 o’clock is unusual. Maybe those big Tannoy speakers go very loud at 12 o’clock ?? Or maybe an issue with your cables ???
If there is a rats nest of cheap cables behind your system - all touching each other, the floor and wall -that could be to blame here, maybe.


I get a buzz from my speakers but it goes away if I turn off an LED lamp elsewhere in the room.

All comments seem as expected/normal in a sense!

The wobbling connectors are a decoupling to reduce noise from vibrations.

Naim use toroidal power supplies to convert the AC mains input to a DC output voltage, these give better stability and cleaner DC but are prone to interference, especially from sources of DC on your Mains circuits, things like fridges for example are noise sources.

A lot of people end up having a dedicated mains radial circuit installed to isolate the equipment from potential sources of noise, this will usually improve the hum issues and the system will be happier and sound better as a result typically.

Cable dressing, how you arrange your cabling, is important and can effect the sound overall, choice of speaker cable is also important as this is considered a part of the circuit overall. A good starting point is the Naim NAC A5 speaker cable, that usually works pretty well in most scenarios, other speaker cable can be well matched but not always the case, worth checking against the recommended tollerances.

If you haven’t done yet it’s worth reading the manuals for your products which if you don’t have the printed copies are on the Naim website to download and read.

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Hi iinaim & welcome!

I suspect the electronic hum through the speakers that you are experiencing is because the signal earth in the Nait5si & mains earth are separate. The link between the two is expected from a single point usually from one of your source components - your Marantz cannot provide this as its class 2 (double insulated).

You can prove this by connecting a wire between the mounting screw of a wall socket and the outer of one of the RCA input sockets to see if it suppresses the hum.

If so you can make a more permanent lead for this purpose.


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Welcome to the community.

All previous replies basically cover all your questions. I will only speak from experience, as I had the amp for like 3-4 years and went through all those topics you mentioned. One thing that I can tell for sure is the hum from the speakers is due most likely to cables close or touching one another, had the same doubt myself and I was wondering for maybe one month in the beginning when I first bought it what was the issue, and it turned out my interconnect from the dac to the amp was touching the power cable of the amp and realized this when moved them accidentally.

Other than that it is a great amp, and I only had to sell it as it was struggling with my speakers being hard to drive ones, 4ohm/87db. Yours are relatively easy to drive so this should not be an issue for you.

best regards

Yep agree with all the above. Had mine about 2 months and the transformer buzzes loudly when either washing machine, dishwasher or hairdryer on. 12 on the vol is loud! around 9 o’clock is plenty for me and amp is silent through speakers. It’s a great amp with plenty of drive and does the hifi things well and communicates the music well
Enjoy it!


Never owned a 5si but did own the original NAIT 5 for some time, loved that amp, was always enthusiastic and musical and was in many respects the root cause for my subsequent Naim journey that continues to adapt and evolve!
Setup is really important and thinking of that as a complete system from mains to speakers. Cabling, racking, positioning and setup of the system in relation to the room can make the difference between a system that sounds ok and one that sounds really quite special.


Sounds like my experience as well. Great amp but I upgraded to the XS-2 and have been hooked on Naim ever since.

Welcome iinaim!

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Try turning off everything in the house. Just do it from the mains - everything except the power that goes to the amp.
if it still hums in a way that it is unacceptable, it’s probably a faulty transformer.
I’ve had tonnes of Naim equipment. Only a Nap300 buzzed too much. Naim replace the transformer on it.

I agree that such a transformer hum isn’t ordinary and would bug the living daylights out of me. Had this once on an SN2 which was resolved by 2 methods:

  1. Built a special ground ground cable. Attached to ground screw at rear of amp and plugged into grounded wall outlet. Ground conductor only, no power leads. Fixed the hum.
  2. Finally installed a dedicated mains spur powering the hifi units only. Also fixed the hum. There is none whatsoever at this stage.

Point one is quick and easy to test. Otherwise, back to dealer to reproduce anomaly in situ.

Hello and welcome to the forum, here you will find many interesting things and many useful discussions … You will see that slowly your whole world and your sphere will be Naim, you will become a maniac of Naim. Everything you wrote is quite normal, I’ve had it for 5 years and I can’t change it, even with a XS3 just released, this 5si satisfies me a lot more! Keep it always on and you will see that once the capacitors are charged the noise will be very but very light, use the volume between 9 and 10 o’clock. If you notice at lower volumes tending to 7/8 o’clock on a speaker it will be a sound or rustling greater than the other. A good rule is to isolate the integrated amplifier from the support surface. Change the power cord to a better one now and enjoy more. Last tip is to put near a steamer like nd5 xs2 and then you would be at the top. Good music


Very well said Andrea! For me my world changed even more once I purchased the nd5 xs2 and stopped playing around with alternate streaming sources (learning experience so not all bad times).

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Hi All!

Thanks for the quick and very helpful replies. :slight_smile:

I tested with wires crossed or not and nothing changed. My speaker cables are oxygen free copper at 14 AWG thickness. Tried the amp free standing or stacked top/bottom and again no change.

I also tried the grounding by running a wire form a wall socket’s ground to a screw at the bottom of the amp (similar to this: Naim 5si hum / Sonos ZP90 – see images/comment from james_n). That didn’t reduce the hum nor the buzz in the speakers. The buzzing reminds me of a guitar going through an amp. (a side note – The buzz in the speakers is becoming audible at around 12 o’clock with connected/disconnected source; no signal is going in/out.)

I am starting to think that the transformer hum is one of these things I will have to get used to. I think it is a mechanical hum and I would say that it is normal however I would expect this from a cheaper product and a less renowned company. Maybe I need to get in touch with Talema and discuss it with them. Anyone tried changing the transformer with something better?

On another note the sound is amazing. So far listened to prog rock, classical music and r-n-b. It just sounds solid, detailed and balanced at all volume levels. Power aside, are the higher range products much better?

Thanks and stay safe!

Hi iinaim,
You need to connect the amplifier end of the wire to the signal earth, not the chassis earth. Try the outer of one of the RCA input sockets.


Hi Neil,

Thanks for the explanation :slight_smile:
Re-wired and the buzz is greatly reduced. Now there is just hiss varying with the volume (which I think is normal) and at max volume is more of a hum than a buzz.

The transformer hum stays the same.


U won’t need max volume in real life.

It should top out at 11 o clock ( high SPL / get very loud )

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