Chassis or Float? which is the best..

Unless you have a source like a CD player Id put it on chassis. 

If you have another grounded source e.g. a CD player connected put the switch to floating, otherwise ground...

Yeah I don't have anything else plugged, other than the TV via optical but the ethernet is CAT6a which is screened so earthed via the NAS too.   

spacey posted:

Yeah I don't have anything else plugged, other than the TV via optical but the ethernet is CAT6a which is screened so earthed via the NAS too.   

Ethernet screen should not be considered as an earth,  in fact its advisable to only have a network earthed at only point.     The SU RJ45 port is shielded & connected to its power supply earth,  QNAP is also connected to earth via its SMPS,  but what connects the two ethernets ??  is it via the wireless hub ??  or a pukka switch ??.     Wireless hubs don't have shielded ports to carry ethernet screen connections so are not a problem.  But some switches do have shielded ports & in this case its advisable to put a break of some sort in the screen between SU & NAS.  

thanks Mike, yeah it's a BT wireless router. Didn't think about the fact that the hub is all plastic bodied so the earth to the QNAP can't be Connected 

In my case there is a little hum on chassis but the sound is more punhy. On float its dead quiet but more relaxed. I prefer the chassis despite the small noise. 

Pyrrhon posted:

In my case there is a little hum on chassis but the sound is more punhy. On float its dead quiet but more relaxed. I prefer the chassis despite the small noise. 

good to hear that you let your own ears decide!

I can't hear any difference either way, so best left on ground then - cheers guys 

In the past 12 months I have added a Meridian 200 CD transport and a Lehmann Black Cube SE II phono stage (with PWX off board PS) to my system.

The Meridian unit is double insulated and there is no earth pin in the socket, so I am convinced that it has no mains grounding.

I am not sure about the Lehmann though, but I suspect the PS is earthed. Or perhaps it does not matter at all because the PS is not directly connected to the system anyway? Any thoughts? My electrical / electronic knowledge is rather poor, so please be gentle guys.

Hi Peter - from the system you list in your profile you have a known signal ground to mains earth ground in the NDS. In addition you have another possible connection from the turntable and the Lehmann phono stage. The Meridian 200 is not an issue - as you say it has no mains earth connection and the S/PDIF connection to the NDS even if it is via coax (rather than optical) is transformer coupled. 

You don't mention any hum problems so all looks fine with regards any ground loops. As a simple experiment you could try setting the NDS ground switch from Chassis to Float and see if there is any SQ difference. If not then leave in the Chassis position. 

James

Given the choice. It could come down ultimately that this switch is a Heterological switch.

TOBYJUG posted:

Given the choice. It could come down ultimately that this switch is a Heterological switch.

It is, perforce, mechanically autological (evidence: the haptic feedback on changing its position and the visual state thereafter).

However certainly for the ND5 XS I previously had, using a continuity tester, I was able to prove that it's electrically autological as well.

james n posted:

Hi Peter - from the system you list in your profile you have a known signal ground to mains earth ground in the NDS. In addition you have another possible connection from the turntable and the Lehmann phono stage. The Meridian 200 is not an issue - as you say it has no mains earth connection and the S/PDIF connection to the NDS even if it is via coax (rather than optical) is transformer coupled. 

You don't mention any hum problems so all looks fine with regards any ground loops. As a simple experiment you could try setting the NDS ground switch from Chassis to Float and see if there is any SQ difference. If not then leave in the Chassis position. 

James

 

Thanks James. I actually do not have hum problems. I asked because I wished to follow Naim's recommendation, i.e. "Chassis" if no other sources with ground and "Floating" if otherwise.

How can I check whether the Lehmann is earthed?

Hi Peter - that's good. With the TT connected to the Lehmann and the Lehmann disconnected from the pre-amp Just measure continuity between the earth pin on the mains plug of the TT and one of the outer rings of the RCA sockets on the Lehmann. Do the same but this time with the Lehmann's mains plug earth pin instead of the TT.

No continuity means no signal to mains earth from this source and you can follow Naims recommended Chassis setting. 

If you don't want to do that, then just try changing the switch setting and seeing if there is a difference in SQ. You won't blow anything up.

James