Sonos connect/Nait 5 I buzz from speakers

It sounds like an earthing issue.  The Nait 5i is properly earthed (i.e. does not float the earth), so it may well be effectively grounding the Sonos through the signal ground - thus very noisy.  I don't know whether the Sonos has anything where you can attach an earth wire.  Perhaps someone who knows the Sonos Connect better than I do can assist here.

i have a Sonos connect that runs its digital signal trough a Arcam Dac into my grounded Nait XS. Only the tiniest bit of buzz with a fully open volume. Have you tried if the buzz changes when reversing the powerwire at the back of the Sonos? The right phase should be where i put the arrow.    

To me it sounds like there is kind of ground loop.. Although as the Sonos has floating earth, it feels strange.. Unless perhaps you are using shielded Ethernet leads..

Any way if you can check it's not shielded Ethernet issue related, by unplugging Ethernet and see if hum is still there, I would then try a ground loop breaker on the audio out. Put ground loop breaker into Google and buy options and take it from there..

I guess the problem is that the Nait 5i uses the source as an earth reference. It was designed on the understanding that it would be fronted by a source of at least of CD5i standard.  If you were connect up a Naim CD player (or similar signal earth connected player from another maker) then you'd probably find that the problem on your Sonos disappears completely.  

There was a thread recently about this and the issue was solved by running an earth wire between the offending device and the chassis of the Nait 5i.  Try doing a forum search.

The Sonos looks to be a fully double insulated design with no earth connection. I 100% agree that this an earthing issue. From previous experience, I would say usually say a buzz rather than a hum is lack of signal ground.  If this wasn't a NAIT5i, which I didn't realise until today is different from other NAIM amps in that signal ground is tied to mains ground. I would have recommended grounding one of the spare inputs on the amp. However as the amps signal ground is already tied to earth, this most likely won't help. A suggestion would be to try a ground loop isolator inbetween the Sonos and the NAIT5i. This may improve things. Another thing worth trying is trying to ground the outer of a an RCA connector at the Sonos end (As Richard suggested). But it could well be that the Sonos is a very noisy design that is not suited to the NAIT.  I went through this exercise years ago with a Yamaha AV amp, which I ended up ditching in favour of a Denon as I just couldn't get the two to play nicely. The other significantly more costly option is to use a DAC between the Sonos and NAIT via the Sonos optical out. But you could end up paying more for the DAC than the Sonos.

casa7, do you have e seperated DAC with a optical connection?

Bizarre, and the buzz occurred only when you plugged the Sonos in and your Squeezebox? 

Oh well at least you have it sorted... Something about this doesn't feel right to me however...

 Glad it is sorted, it does highlight that you still need signal ground tied to earth at one point. I would say it is a completely safe solution. Slighty puzzling though is that it contradicts the advice given that the 5i doesn't  have a floating ground.

SB, while the Nait 5i is mains earthed, it does not have a signal earth to mains earth connection - it relies on the source for this.

my Goldnote phonopreamp has some serious high frequency buzzes when the CD5i is not connected to the mains block.

In this circumstance, it's the lack of a connection from the signal 0V (the shield of the RCA or DIN connectors) to protective earth (i.e. mains Earth).  With Naim systems that's provided by one of the source components not the amplifier for sound quality reasons.

As the Sonos is double insulated and not earthed, you'll need to provide an earth connection for the signal yourself (which you have done).  This is safe.

Richard are not all or most Naim NACs built this way? and in the past typically the CD player provided the source earth ground and other Naim sources devices have a switch to float or connect ground to earth?

I am intrqued as on my 202, 282 and 252 I never expiereiced hums from floating sources, although bass and dynamic performance and overall naturalness and feel seemed to improve with at least one directly earth grounded source connected to the NAC.

Simon

Simon yes, they are.  Signal to earth connection is in the source - all Naim CD players are this way.  It's why, if you have two Naim CD players connected to the same system then you need to lift the signal to earth connection in one of them, otherwise overall SQ is impaired.  It also negates any meaningful comparison between CD players (if both have a signal to earth connection) if both are connected to the pre-amp at the same time - you need to ensure that one has the i/c disconnected.  Of course, the DAC and streamers come with a handy switch to either connect or float the signal earth, which makes using them in an existing system that may well have a Naim CD player (or other brand such as the early Meridian CD206 as just one example) much easier.

Richard, thanks for confirming. I also have expierienced if you have a Hugo connected to a NAC the overall NAC performance is improved (quite distinctly) by connecting a Naim CD player such as a CDX2 or a Naim streamer with the ground switch set to earth to one of the other NAC inputs, but if you have both say the NDX and CDX2 connected then you need to slide the NDX ground switch to float. In my setup I hear no hums or buzzes if incorrectly set up, but the audio simply improves as I described above when the earth grounding is correctly set.

Simon

Simon, yes, I concur.  Also worth bearing in mind that earth loops that can degrade audio performance are not always audible as buzzing or humming, just as degraded audio...