NDS Signal Ground Switch
Posted by: pz on 19 August 2016
Currently I have:
NDS+555PS DR, CD5XS, SN2 + HICAP DR.
CD player connected to NDS by Naim DC1 digital cable.
My primitive question: what positon of NDS' signal ground swirch should be chosen in this case floating or chassis ?
Thanks in advance.
Is it? I have my CDX2 connected to my NDac via DC1 and use the floating earth setting on the NDac. Thought all CDP's had the central ground and therefore everything else should be set to float?
If your unaware of the effect this can have on the sound I find that on the correct setting you will get a much more tangible image. If switch to the chassis earth I get a slight left/right phasey sort of sound and a slightly lumpy bass.
I think Alba is right.
I believe that the coax S/Pdif input of the NDS is galvanically isolated, so the 0V to Protective Earth connection in the CD5XS isn't tying the 0V line of the NDS to Protective Earth. Therefore this needs to be done by setting the NDS Signal Ground switch to 'Chassis'.
Leaving it set to floating isn't dangerous, so you could confirm by listening (listen for less background clutter, cleaner bass response, better mains noise immunity and/or better soundstage / sonic imaging). If both are grounded, then in addition to not getting the above advantages you'll also find the system prone to mains hum through the speakers (in the correct position the 100Hz tone should be inaudible - N.B. no music playing!).
Okay, this makes sense. I'm using my CDX2 as just a transport but also have a Armageddon/LP12 attached, which may be giving the earth reference and why my NDac sounds better on floating?
Alba1320 posted:^ Chassis.
Correct. Only if your analogue signal outputs of your CDP are connected to your NAC should you have the NDS set to float.
The Naim CDP earth grounds the signal ground. The NAC for optimum operation must have one and only sone signal input set to earth ground. So if you have a CDP analogue signal connected, all other inputs must be floating.
Simon-in-Suffolk posted:Alba1320 posted:^ Chassis.
Correct. Only if your analogue signal outputs of your CDP are connected to your NAC should you have the NDS set to float.
The Naim CDP earth grounds the signal ground. The NAC for optimum operation must have one and only sone signal input set to earth ground. So if you have a CDP analogue signal connected, all other inputs must be floating.
Some people pay for this kind of information!!! We are lucky to have Simon on board!
indeed Simon helped me ground my 282 and 202 and both now sound consistently great.
when they were floating they sounded good time times and not so good otherwise.
now both sound good, every time, every day.
Thank you again Simon.
Grrrr.... ![]()
I've just checked my systems - both had wrong settings.
Changed both systems to:
1. Single source system (in my case NDS) - should be set to Chassis. This way the source is properly grounded. Small change in the audio presentation - almost no difference.
2. Multiple sources, digital connections to nDAC - nDAC set to Chassis, CDX2 (digital out), NDX (digital out, groundingset to Floating). Significant change and sound improvement.
Adam
by the by.... whoever wrote that section on the ground switch setting in the manuals should be 'grounded'. It's utter nonsense with double negatives.
+1 on the manual. Added problem is it gets even more complicated when used with non-Naim components & how to find out if a component carries a grounded analogue signal; OK its easy if it has a two wire power cable, but what if its a three wire. Best tool is your Mk-II audio receptors.
Mike-B posted:+1 on the manual. Added problem is it gets even more complicated when used with non-Naim components & how to find out if a component carries a grounded analogue signal; OK its easy if it has a two wire power cable, but what if its a three wire. Best tool is your Mk-II audio receptors.
Good point Mike! Had the same dilema on how to hook-up Oppo 105 (it has 3 pins) to an NDS. In the end settled on an optical cable - complete galvanic isolation between the components.
Mike-B posted:+1 on the manual. Added problem is it gets even more complicated when used with non-Naim components & how to find out if a component carries a grounded analogue signal; OK its easy if it has a two wire power cable, but what if its a three wire. Best tool is your Mk-II audio receptors.
Does anyone know how an LP12, connected via Stageline would impact the NDS setting?
Keith
Chag
The NAT manual does not seem to mention the grounding. I'd therefore assume that it is properly grounded, like a NAIM CD player.
Therefore NDS would be set to 'Floating' to maintain only one grounded connection for the whole system.
Regardless - test it.
Adam
The Stageline is powered from Pre-Amp or PSU +ve & -ve & the signal is not connected to earth, so NDS is set to Chassis
Chag... posted:
As I understand it, the NAT-05 is connected to earth at the case only, as are all Naim components, the signal section is not earth connected. I have my NDX with NAT-05 set to Chassis.
Thanks Mike. My NDS has also been set on "Chassis" but was starting to doubt.
Chag -
Correct; traditionally the primary source (usually the CD player) has provided the signal ground and main ground connection. The tuners do not have signal ground connected to main ground. This also means that if you have two Naim CD players connected to a Naim system at the same time then you have two signal to main ground connections and this will impair overall performance and make any comparisons between the two players useless. The recommendation was to have Naim lift the signal to main ground connection on one of the players (an internal job) if it was to be a permanent arrangement, or to only have one player connected to the pre-amp at any one time. With the arrival of the Naim DAC and streamers it was realised that many would run them alongside existing Naim CD players, hence lifting the signal ground connection was made easier via the rear mounted switch.
Cheers Mike, much appreciated.
Thanks Richard,
Your reply suggests that the grounding switch is for Naim CD players, although it is possible that other manufacturers' players may require the floating setting.
Finally, I have an Arcam AV amp connected via the unity gain setting with a ground loop isolator. I assume this is ok too, so I should stick with chassis?
Intrigued by all this I've just had a fiddle playing iRadio on NDX & BBC R-3 on NAT-05. I reset my NDX to Floating & found it did not make much of a change that was that obvious, maybe a touch less focus in soundstage & something a bit vague in the general SQ. Resetting back to Chassis confirmed this. But with only NAT-05 & TT as extra sources to the NDX, & as neither have a signal ground connected to mains earth, I was not expecting it to be radically different.
I seem to remember Richard Dane saying that the CDX2.2 needed to be re-booted when switching from analogue output to SPDIF to effect the change over. Would the nDAC need re-booting when switching from floating to chassis or visa versa to effect the change.
sheffieldgraham posted:I seem to remember Richard Dane saying that the CDX2.2 needed to be re-booted when switching from analogue output to SPDIF to effect the change over. Would the nDAC need re-booting when switching from floating to chassis or visa versa to effect the change.
Re-boot is only needed on the CDX2.2 when changing from analogue to digital outputs.
Grounding switches (also nDAC) on other components do not require a re-start.
Is this only appropriate if using a Naim pre or integrated ? Nothing in my Karan manual mentions anything about reference ground on the inputs. I have my ndac set to chassis, but will it compromise it's performance if set to floating - personally can't tell any difference, might be because in my system in doesn't make any difference ?
The most important thing is to listen and decide on a setting you prefer.
With a no-Naim amp, I would hazard a guess you are using DIN to RCA connections? This way you already have to 'negatives' and no earthing continuity. So I can imagine the switch on your nDAC might as well be set to 'floating'.
No I'm using the RCA output from the ndac
!
TOBYJUG posted:No I'm using the RCA output from the ndac
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Same difference ![]()
TOBYJUG posted:No I'm using the RCA output from the ndac
!
Makes no difference - the same principle applies to RCA/phono or DINs ![]()