Proper Signal Ground

Streaming Audio
1

Just wondering how members are achieving a proper “signal ground” in their Naim or Naim hybrid systems.

One scenario I had in mind might be:

Naim Uniti Core > Chord dac > Naim pre/power.

With the above, is proper signal ground achieved?

That is, without a Naim CD player or turntable installed.

Also, I am unclear if a cd player is to be used for system signal ground, need it be a Naim player?

Are the din type interconnects used in Naim CD players and preamps the important variable here?

2

The Core won’t come into play for signal grounding here.

One thing I find really useful with non UK brands is they often publish circuit diagrams of their component’s signal paths so you can understand the exact arrangement and grounding. Often it is commoned to the return (-) on one end of the connection (either amp or source) and a discrete earth lead is not required. Even if you don’t read electrical diagrams, as long as you understand the difference between the three earth icons (ground, chassis, and signal), you can follow where they go and whether they end up unterminated. A signal ground should end up connected to something on Chassis or possibly Ground (less common). You’ll have no such joy with the Naim or Chord manuals sadly.

I’d suggest that for a really definitive answer, you ask Chord about the signal ground on the specific DAC and whether it has additional requirements beyond just hooking it up to any amp.

3

Thanks much Zen for your thorough response on this topic, much appreciated.

My 282 pre amp provides a ‘signal ground’ screw terminal on the back.

Perhaps I can utilize this in some way in my set up.

I imagine it’s best to eliminate as much noise as possible in one’s system…

4

Signal ground is not like chocolate. More is not better. As such, the ground post on the 282 is specifically for sources with a signal ground out, like a turntable and a some rarer digital sources.

I would certainly check with Chord about the signal grounding for your specific DAC. There are interconnects with a third trailing signal ground connector (thinking of Atlas here) but you almost never require them. In addition, I think the ground post on Naim preamps is a highly unusual “signal ground in” with the expectation that signal ground goes out to a Naim source and is grounded to chassis there.

Given that there are a massive number of Chord users on the forum and none have mentioned additional signal grounded to my knowledge, I’d definitely check before doing. It is very easy to make things noticeable much worse by grounding the wrong way or too much and creating a loop.

Generally speaking a signal ground is an output. Which connects to something with a chassis ground. The item offering chassis ground then might not connect to earth ground unless it has a shunt to prevent noise (and quite a bit of noise at that) flowing back in. Basically, you never connect signal ground direct to earth ground provided via the mains.

5

Once again Zen thank you for the interesting information, and advice in your last post.

6

This should be straightforward. The Naim DAC has a signal ground switch on the back, under the RCA sockets. Ensure that is set to chassis if no CD player for correct grounding. (Assuming there are no other earth grounded sources connected to the NAC)

The SPDIF connection from the core to the DAC is galvanically isolated… which means the grounds are decoupled and separated.

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7

Not quite, I have mentioned this a few times on the forums over the years about the need for correct earth grounding for optimum performance. When I was running a Hugo into my 552 I would ensure an earth grounded source such as CDX2 was also connected to the NAC. The earth grounding is achieved even if the source input is not selected. If the grounding is not right on some of the Chord DACs they can sound a bit indistinct in the lower frequencies.

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8

Thanks for your reply Simon.

My system probably is covered for proper grounding in all respects if I understand correctly?

Thanks

9

Sounds like it if your Naim DAC signal ground switch is set to chassis.

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I thought we were talking about Chord DACs here rather than the NDAC?

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Ahh yes… so the NAC will need a ground reference point…

12

I recall keeping a standard DIN cable between NDX and 282 when I added a Hugo to my system (possibly your idea?) but of course the OP can’t do that with a Core.

13

Something like Atlas Grun should do the trick then. They even show this being used with a NAC on the Grun page within Atlas.

Oddly enough, Atlas don’t have a lot of details about these. They are about $200 and I would hope they employ a proper earth shunt in the plug. Any signal ground connected to mains earth direct is likely to sound immediately far worse than none at all. Hence earth to chassis or to a dedicated earth ground with shunt.

14

Yep that works well as well, and I used when I didn’t have my CDX2 hooked up. Obviously NDX2 signal ground set to chassis… and din connected to NAC… even though you are not using its audio output.

15

The 272 I just picked up is set to “floating”. The only thing I have connected is the 250DR and a QNAP NAS on the network. It sounds like I need to have the 272 set to “chassis”.

16

Yes.

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