Someone told me there could be a ground compatibility issue due to Naim’s use of a “floating ground.” I was told the smaller Chord products can have this issue when used with Naim.
I get a pretty pronounced hum through both speakers when my Chordette Gem DAC is used (predecessor to the 2Qute). The hum gets louder as the volume increases. I’ve isolated the cables, tested other components, etc. It only happens when this DAC used.
I have a Naim 152/155 XS set with Dynaudio Focus 160 bookshelves.
Naim simply requires one of its sources on its NAC inputs to be earth grounded.
Traditionally this is the Naim CD player.
Other Naim sources have a ground selection switch to compensate if you have no earth ground elsewhere such as a Naim CD player.
So with Chord as with most other sources with Naim you best ensure you have at least one Naim source that is set to earth ground.
In practice most Chord devices seem capacitively coupled to earth ground, so they will work fine, but the noise floor might be minutely raised and you might find a slight loss of very deep bass performance if there is no formal earth ground… but minor impacts really.
As far as SPDIF with Naim digital source products, Naim use galvanic isolation so there is no possibility of earth loops there.
I previously used Hugo with SN2. I got hum when Hugo was the only thing connected, cant remember if Hugo was running on batteries or connected to mains. Anyway, the problem was resolved once something else that was connected to mains earth, such as the TV, was connected to the SN2. I was going RCA to RCA.
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.
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.
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?
@Slamdam 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.
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.