It does in my system. It’s not really today’s news that you can cut a ground loop using optical connections. Do you want me to record a video? Are you claiming I’m providing false news?
What Naim transport are you using? As far as I am aware Naim only provide galvanically isolated SPDIF output.
This thread is about Chord / Naim comparability.
Yes a video of your Naim digital optical output would be interesting… especially for Naim.
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SN2 and ND5XS connected to a Onkyo CD. With coax I get loud hum. With optical dead silent.
I don’t believe Chord and Onkyo are the same company?
This thread is about Chord and Naim. Inserting other random vendors in here is going to clearly mislead.
And of course in your example with Onkyo, you don’t state what the all important ground reference was set to on your Naim products. It looks like it was set incorrectly for your CD player and set an earth loop which causes an induced hum.
This is one of the reasons why Naim provide that little switch on most of their sources to avoid the scenario you describe. Your dealer should have advised you of this when they set up your system. But if in doubt and your dealer can’t advise, always contact Naim customer support and they can help.
Often very simple remedies for these sorts of issues.
I had a 2Qute in my system for a week with no issues (other than sounding rather too clinical) but I think I had a DVD5 providing the signal earth.
Can you find an earth binding post on the back if the pre amp? Connect a wire to this and, if you’re in the UK, touch it to the screw holding a wall socket to its backing box and listen for the hum, if it goes away you can than look to arrange a more permanent connection. I’d use the earth pin of a plug but I’d be very certain there’s no possibility of contact with live or neutral.
Never needed to do this myself, but I wonder if @james_n suggestion here would help:
It doesn’t seem to be necessary on the Hugo and other Chord DACs in my limited experience, but perhaps the older Chordette is different. Either that, or we’re barking up the wrong tree 
Only the ND5XS has the ground switch as master of everything everyone else is wrong probably knows. Changing it didn’t make any changes. Solving the problem was a 10USD optical cable breaking the ground connection between my non-naim product and naim.
The ground switch is affects audio only… Naim digital outs are galvanically isolated.
It looks like your CD player SPDIF output was not galvanically isolated which it really should be.
So yes in such circumstances where your suspect your digital source is not appropriately galvanically isolated such as connecting many TVs and STBs to your digital inputs, then use Toslink.
I don’t know what is and not is and all technical stuff. I’m just saying a 10USD optical cable very well can solve hum issues as did for me and many others. If you then think it’s worth trying or not then up to you. Just want to help you know but being accused of lying is quite a jump Mr.
Calm down, we were talking about a Naim and Chord as per the thread… and you randomly brought in other vendors without initially stating that… please be clear… as it looks otherwise as if you are stating untruths/misinformation as it appeared here.
Anyway I am glad you found a way to connect your Onkyo CD player digital output to your Naim… why don’t you start a new thread advising that?
@Blackbird you needed a grounded coax digital lead. Many on the market. I used an Audiotechnica one in the past and the interconnect had an earth dongle at on end to affix to the chassis earth of any supporting unit.
I suspect your issue was a combination of not knowing the requirements of the Onkyo and wrong cable.
A chord qutest connected to my SN2 caused a large hum through my speakers. I connected another source to the amp which resolved the issue.
@Pedropete exactly my experience with Hugo.
I’m sure this issue was well documented many moons ago on both the old Chord Electronics support webpages and in the old Naim forum.
Pedropete, if you look at the SN2 manual it says
4.10 General Connections Notes
The SUPERNAIT 2 negative input and output connections for each channel are common. The mains earth (ground) should always be connected regardless of what other equipment is used in conjunction with the amplifier. The mains earth only grounds the case and the electrostatic screen within the transformer, and is not connected to the signal negative. In order to avoid hum loops, the signal negative of the whole system should be connected to the mains earth (ground) in one place
Therefore you need to ensure one and only one source is earth grounded.
Chord, like many manufacturers don’t earth grounded their sources, therefore with connection to Naim you should ensure you have another earth grounded source connected to the NAC inputs, or manually earth by careful DIY your one and only floating source.
This has been discussed many times on earlier forums…
This is Naim’s design to star or centralise the ground so as to minimise the noise floor.
BTW of course the earth grounded source doesn’t need to be selected or active for this to work… it simply needs to be connected to the mains, and the audio lead output connected to the NAC input.
I can add that my house and all houses built up to 1994 in Sweden have non grounded outlets in all rooms except bathroom and kitchen. Not sure how that is in UK. But as always it’s the customer doing wrong when using Naim even though it’s only with Naim I’ve had buzzing transformers, ground loop issues etc. Strange.
I think Sweden and Japan are alone in the world for non grounded outlets.
Naim stuff must be mains earthed or not used.
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On my SN2 with the original Hugo in some configurations there was a buzz. If I remember rightly I took a weird from the ground screw to the outside of one of the din plugs and it was resolved. No issues with 282 and any of my hugos
Our apartment in France was the same, presumably to save money when it was built in the 70s, there was even an earth cable passing behind some of the unearthed sockets in the living room. This is one area that could usefully be harmonised in Europe and probably has been by now even if the socket format hasn’t. At least appliances that require an earth would be safe to use anywhere within the single market.
Well a grounded outlet is more safe but if that statement would be true homes in Sweden and japan would be empty of electrical equipment which is not the case. Many professional studios here are also non grounded and you can and are allowed to connect grounded equipment to non grounded outlets but not the other way around and never mix grounded and non grounded outlets in the same room.
Well it couldn’t be more different in the UK. You would unlikely have liability insurance and be, almost certainly, in breach of health and safety regulations if you were to use a non earthed mains setup in a professional setting with equipment designed to be earthed… also you would not be able to get the work certified.
Many professional studios and such like will use a TT earth system with local electrode to help reduce the noise floor.
In most domestic settings in the UK, PME (TN variant) solutions are used instead… its can allow more consistent earth leakage safety but at the expense of increased noise on the earth… that most don’t care about, and if it is important you have the option often of TT.
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