NDX and grounding switch

Posted by: overprint on 21 July 2016

Apologies if this has gone before - but what is the correct slide position for grounding on my NDX?

My Nac-52 has the NDX, a tape deck and an LP12/Prefix connected (powered via socket 2b). The grounding wire from the LP12 is screwed into the black connector at the back of the Nac-52.

Posted on: 21 July 2016 by Simon-in-Suffolk

all depends on what else you have connected to your NAC. If you have another earth grounded source like a Naim CD player then the slide button on the NDX should be at float.

The requirement is to have one and only one earth grounded source connected to your NAC audio inputs. So if your LP12 and Tapedeck all have have floating signal grounds then the NDX should be set to chassis ground.

If you don't know - you will need to unplug the components in question completely - leave for 10 minutes - and then get an ohmmeter and measure the device-in-question's resistance between its signal ground and its main earth plug pin  (remember you have disconnected everything and let it stand for at least 10 minutes). If the ohmmeter reads more or less zero then that device has a grounded earth.

S

Posted on: 22 July 2016 by Huge

If it reads less than zero, you haven't left it long enough.  

Posted on: 22 July 2016 by Simon-in-Suffolk

Huge .. perfect .. out of everyone here you are the one I would have predicted such a comment 

Posted on: 22 July 2016 by Huge

Simon, I'm concerned for your sanity - you seem to be starting to understand my twisted sense of humour.  

Posted on: 22 July 2016 by overprint

Simon

"and measure the device-in-question's resistance between its signal ground and its main earth plug pin  " - errr, how do I do that (stop sniggering at the back there! This isn't my area of expertise). 

Posted on: 22 July 2016 by Mike-B

If you don't know how to do it, it most likely means you haven't got an ohmmeter, so best leave it.

Posted on: 22 July 2016 by Simon-in-Suffolk

yes - if it all sounds double-dutch - best get the advice of your dealer - they  should know how to do this

Posted on: 22 July 2016 by james n

No damage will occur if the switch is in the wrong position. In some systems hum can result, in others there is a subtle improvement in SQ with the switch in the 'right' position. If you've not got hum and not sure about the grounding of the tape deck and Linn then try both positions and see if there is one you prefer. Simple as that 

James

Posted on: 23 July 2016 by Simon-in-Suffolk

James is right, ultimately you can decide which sounds best, but if that inner OCD dæmon in you needs to know what it should ideally be set at then follow my suggestion or get your dealer in.