Sonos Connect causing ground loop buzz


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I've recently swapped my old Rotel RA12 amp for a new Naim Nait XS2.

Great amp, but since switching over I'm very aware of a ground loop buzz caused by my Sonos Connect. I've tried different interconnects, plugging the amp and Connect into separate power strips, even adding a ground loop isolator (which just made the buzz worse).

Bearing in mind my complete lack of technical knowledge or skill, is there an easy way to solve this issue? Someone from the shop which sold me the amp came out and fiddled with various combinations of fancy power strips, super-expensive leads and other things, but couldn't solve the problem. He did suggest, though, that the problem may be because the plug on the Connect isn't earthed.

Any suggestions on a straightforward solution?

59 replies

The Connect is not known to cause this, something reinforced by your experience with the Rotel. The Naim may be defective. See if using another jack on it solves the problem, in which case the one jack on it may be defective.
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Thanks for the quick reply, Kumar. Unfortunately, different jacks didn't make any difference - and the guy from the hifi shop brought an identical Naim amp to check as a last resort, and we had exactly there same buzz from that as well.
If the Rotel or any other amp is still with you - what happens if you use that now?

Also, the Connect has digital outputs as well; if the Naim has the corresponding input jacks, you could try that as well. I am not ruling out a Connect defect, it is just that it arising only after an amp change leads one in a different direction.

Another shot in the dark - insert the pins of the Connect into the mains socket the other way around and see what happens. Do this first being easiest, then the actions above...
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Thanks for your advice, Kumar. It is very much appreciated. Unfortunately, the old Rotel amp has been sold, and the Naim has no digital inputs. I've experimented with using the available nine-pin DIN sockets instead of the phono inputs, but that hasn't made any difference. Also, I'm in the UK, so a three-pin plug is the only option - so no chance of moving pins around, I'm afraid.

Also - in the interests of full disclosure - I can't be 100 per cent sure that the buzz wasn't there with the Rotel amp as well. I don't remember ever raising the volume loud enough without any music playing to find out! I only became aware of it with the new amp because I was running the Naim through its paces and checking I'd connected everything back up properly after getting rid of the Rotel (whereas the Connect was added to the existing Rotel system last year).
The Naim is rare in having a ground socket at the rear. Have you used it? Check the manual for why it is there and when it is to be used. Change from whatever status quo there is on its use and see what happens.

Finally, what happens from any other sources like a tuner or CDP playing via one of the input jacks? Or even iPhone if you have one at hand?
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I've swapped the various components around in the input line-up, just in case there was a problem with one set of inputs, but the only constant when it comes to the buzzing sound is the Connect. There's no buzz at all when the CD player, phono stage and even my old cassette deck (brought up from the cellar for a test) are connected. But as soon as the Connect is plugged in, the buzz starts up. Likewise, if the Connect is the only thing connected to the amp, the buzz is there.

I'm nearing the point of looking for another streaming solution and trading in the Connect, much as I love it.

(thanks for your patience with this!)
You seem to have covered all the bases; the only one left is to see is if swapping Connects fixes this. Worth trying before moving to another streaming solution. I am not being a biased fan when I say that there really isn't any better one in the market, so that little extra effort is worth it.
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I agree with you about the Connect being the best of its type. Nothing else comes close as far as services offered etc. Good point about the device itself, though - I'll see if my pals at the hi fi shop have a Connect I can borrow to see if it's a problem with my own unit, or if the problem is common to all Connects. Thanks for taking the time to offer suggestions!
There's one possibility which hasn't yet been addressed: ground float. In other words too little earthing rather than too much.

As an experiment, plug a spare RCA lead into a vacant socket on the CONNECT, then touch the shield of the plug at the other end onto something which is grounded, say a water pipe.

I encountered a persistent buzz when using a ZP80 with a headphone DAC/amp (connected by digital coax). Neither was earthed to the mains, so I butchered a spare RCA lead to ground the ZP80. Now totally silent.

CORRECTION: I grounded the headphone amp. See later post.
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That sounds interesting, ratty - but cleverly exposes my complete lack of knowledge about anything useful! :)

Since the whole hi fi setup is here in my office with no access to anything like a water pipe, is there anything else I can use for this test? And, if so, how do I go about grounding the Connect?

Sorry - loads of questions, but this thing is driving me nuts!
I have used two different Connects with a range of amps and have never seen this. And there isn't the flood of complaints on those lines there would have been if it was a common problem. I suggest taking the Connect to the shop and seeing if the problem is there with other demo amps there -amps of other makes. I have never used Naim, but know it can be quirky.

Good luck!
Ted Maul wrote:

Since the whole hi fi setup is here in my office with no access to anything like a water pipe, is there anything else I can use for this test? And, if so, how do I go about grounding the Connect?


Could you touch the lead onto the chassis of something which is earthed, like a desktop PC?
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Thanks, Kumar. I'm waiting to see if the head honcho at the shop has any other ideas, so I'll keep my fingers crossed.

And it certainly doesn't seem to be a common problem - I could only find one other similar situation, but couldn't see if and how any resolution was reached.
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ratty wrote:

Could you touch the lead onto the chassis of something which is earthed, like a desktop PC?



There isn't anything like that within easy reach. I'm assuming the amp itself or the CD player wouldn't count?
You could try the terminal on the back of the Nait marked 'Ground'. But there ought already to be ground continuity between the amp and the CONNECT, along the existing interconnects. The amp in theory should be earthed, but as an experiment I'd be looking for something external to tie the CONNECT's ground down.

NOTE: I actually grounded via the headphone amp. See later post.
ratty wrote:

I'd be looking for something external to tie the CONNECT's ground down.


Digressing to understand this: how come that using the 2 pin US style socket that came with the Connect cable, I don't see this problem? I thought that the 3rd pin is the one that does earth? All my Sonos kit including play units use the same 2 pin plugs.
I'd better row back slightly. The solution which fixed my headphone amp was to ground it (via a spare RCA), not the ZP. Either way, it was a shortage of earthing which was the problem.
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ratty wrote:

You could try the terminal on the back of the Nait marked 'Ground'. But there ought already to be ground continuity between the amp and the CONNECT, along the existing interconnects. The amp in theory should be earthed, but I'd be looking for something external to tie the CONNECT's ground down.



I've just given that a go - no difference, unfortunately.
Is the CONNECT wired to anything else other than the Naim?
See: http://forums.naimaudio.com/topic/xs-2-speaker-hum

As an example of quirky Naim kit. On the other hand Ted sees this only with the Connect as a source, not if another device is connected to the same input jacks on the Naim, using the same interconnects (?).

IMO, next step is to take the Connect to the shop, wire it to a demo amp of another make and if the hum is missing, exchange the Naim for a 70 ish wpc amp of that make. There is less of a difference between the Naim and any another name brand amp of the same power spec than between Connect and other streaming solutions.
Way back in the mists I had a NAC/NAP/HICAP setup. They are a bit 'different' in terms of circuit design.
And one more on Naim: http://forums.naimaudio.com/topic/hum-noise-and-no-solution-from-naim

With a cut/paste of a strange owner comment on the Naim forum: "The fact that Naim equipment is deliberately designed in a way that highlights problems in systems outside would indeed be reproachable, if they did not offer the inducement of ultimate performance after external system anomolies are resolved."

Quirky, at the very least. Audiophiles love it for this reason, among others.
Ted, on a lighter side, another cut/paste from the Naim forums:

"Stop thinking about how much you spent on your Naim amp.

Stop questioning the hum - it's there for a reason.

In life there are things better left unexplained. Knowledge is pain.

Instead of seeing the fingers, see the space between the fingers.

You need to embrace the hum. Like a mantra. Oooohuuuummm oooohuuuummm oooohuuuummm...

Have some camomile, see a therapist, get into yoga..."

End quote:-))
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ratty wrote:

Is the CONNECT wired to anything else other than the Naim?



No, just straight out from the phone jacks to the Naim.
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Kumar wrote:

Ted, on a lighter side, another cut/paste from the Naim forums:

"Stop thinking about how much you spent on your Naim amp.

Stop questioning the hum - it's there for a reason.

In life there are things better left unexplained. Knowledge is pain.

Instead of seeing the fingers, see the space between the fingers.

You need to embrace the hum. Like a mantra. Oooohuuuummm oooohuuuummm oooohuuuummm...

Have some camomile, see a therapist, get into yoga..."

End quote:-))



Ha! The power of positive thinking! Maybe I should try pouring some camomile tea into the amp to see if it soothes the hum... :)

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