Nait 5si AV mode buzzing from speakers

Hi all, complete Naim newbie here having just bought a Naim Nait 5si from a good friend, so I know the history of the Amp. Got it all connected up including Naim speaker cable. I have a Marantz NR 1711 connected via its pre outs to the AV input on the 5si. I have noticed that there is a low quiet buzz/hum coming from the speakers when the AV mode is selected. Lots of googling and forum reading, left me to buying a cheap ground loop isolater, but that made thing 10 times worse, so it came right out again. Any help would be greatly appreciated, if someone has had the same issue and resolved it.
Many thanks in advance.

I have found a Naim integrated amp one of the more sensitive amps to integrate into varying hifi systems, with regards to generating/‘dealing with’ hum…

generally less than thirty seconds fiven to moving speaker cables and/or subwoofer cablling as well as reorientating signal cabling can vary the amount heard, easily, by a factor of 10-100x…

once I find the cable(s) causing issues, I simply do a long term re-route and haven’t had any further issues with the installs (usually until I swap stuff around haphazardly)…

I do feel a significant part of the Naim ‘more musical’ sound is a result of not having all the chokes in place (like lots of negative feedback to nullify circuit and signal noise etc), so I take the inconvenience of ‘noisier amp’ (until sorted) as a ‘glass half full thing’ and embrace this aspect of the components.

AV Bypass; I’d be keen to look at the cables from preamp output to AV input/‘AV bypass’ input…

In my experience, even curling them a different direction might make the issue go completely away.

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Thank you for the quick response Whitey. The Chord interconnect fro the AV pre out is running completely straight and off the deck, as it’s almost at full stretch. I’ve tried holding it to see if it grounds out, but no change, buzz/hum is still there. Swapped out the Naim speaker cable for Chord Clearway, as the shielding is a lot thicker, still no change. 5si is at least a meter away from the AV. All other modes CD, Tuner, HDD, have no buzz/hum. Think it may be a grounding issue with the Marantz. Thinking of taking a grounding wire from the ground terminal on the Marantz and wiring it to earth of a 3 pin mains plug. I am at a total loss with this one.

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Grounding issues can be very frustrating, especially with trying to integrate AV into a chassis earthed 2 channel system. Naim kit does unfortunately provide a nice route to earth for any floating AV kit. Usually a ground loop isolator does the trick though. Perhaps try grounding the Marantz as you mention and see how that helps.

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Thanks Rich, that kind of ties in with everything I’ve read. I even rang Russ Andrews and spoke to them as I have power chords, interconnects, extension bar etc and they seemed to think it could be the issue. So that’s next on my list to do.

Are all the power chords from the same power point or power board?

Warm regards,

Mitch in Oz.

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Loving the Oberons by the way. I know they work superbly in an AV context.

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All Russ Andrews chords and block for the hifi. AV, Sky, TV etc. are in a separate extension block behind the TV, Mitch.

They are fabulous both in AV but also in the 2 channel also. Nicely balanced and very revealing with the 5si :blush:

Rich, should the isolator be connected at the amp end or at the receiver end, or does it make no difference, as when I connected it up, I put it on the Marantz end?

Luckily I’ve never had to use one myself, but there’s no harm trying either way.

Dear Trev,

Thank you for the pic. If I read correctly, that you have one block for the HIFI and another for the AV, Sky and TV? Or are all fed from the one block. If the former, are they fed from the same power point? I am a little confused still. I am just trying to get a correct mental picture of your setup.

Ideally they should all be fed from the same block and one power point. It is OK to daisy chain blocks.

Warm regards,

Mitch in Oz.

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Cheers (photos!!)

good responces keeping on topic, and focused on the problem,… (yay)

Whilst I DO believe dealing with the cause is always a sound solution to a problem; masking symptoms is often ‘good enough’… (just look at modern medicine!).

Seeing those cables run that way; I have had ‘no joy’ with Naim amplification when leaving cables in standard array (like photos show)

Basics are 90 degree (cable) crossover each other, especially if high level/low level signal (‘different’) and/or power vs signal cables.

I’d even temporarily install a crappy ‘old’ RCA cable set to see if the present 2xRCAs aligned perfectly vertically are not doubling as some sort of nice antenna.

Your ‘dodgey quality’ old RCAs are probably 1-2metres long and will allow moving them in position whilst the system is ON.

otherwise… seeing the power strip photo, looks like some signal/speaker cables might be running parralel to power cables (if even ‘only briefly’); for me this has proven a massive ‘no no’ with a Naim amp in situ.
(with same cable runs proving ‘no issue’ with any other amp combos)

things to consider/‘look at’.

as for source of buzz in a stereo system, can be anything from dimmable lights (rooms away!) to a crappy power pack…
the forum awreness as to how Naim kit ‘isolates’ (or ‘doesn’t’) is probably of the most worth to investigating this.

For me, moving my OLED TV to a different power circuit solved the issue (in one instance)

“fun times”
-that being said; once sorted, is an incredible sound and ‘worth the effort’.

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Hi Mitch, so the RA block holds all the hifi and a second extension holds av, tv, sky etc. bot blocks are plugged into a 2 gang wall socket, I hope that makes sense.

Thank you Whitey,
The only cables I can see that run parallel to any power cables, are Ethernet cables for Sky, TV, Streamer and blu ray. I’ve tried holing all cables, swapping power chords around etc, daisy chaining the tv extension into the RA power bar, all to no avail. Going to try grounding out the Marantz today to see if that makes any difference.

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Update- Problem solved. Made up an Earth cable with a three pin plug, plugged into the mains, and the other end grounding out on the Marantz grounding post, hum/buzz completely gone. Thank you all for your help, advice and contributions :blush:

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I was premature, had the av outputs into the wrong input on the amp! Hum is still there! Grrrrrrr

Dear Trev,

I am perplexed. Could you start disconnecting one item at a time from the second RA Block containing the AV, Sky and TV? Just the power connections. You may have already done this. I had a problem in a church band with buzz, and it was the overhead three-phase lighting being picked up by the pick-ups on my bass guitar, and all the time, I thought it was a ground loop.

This is going to be a slow process of elimination. As one respondent mentioned, it could be your LED lighting from another room. One step at a time.

Warm regards,

Mitch in Oz.

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Morning Mitch,

I think that’s what I am going to have to do, it will also give me a chance to re-dress all the cables behind it too. It’s just very odd, it’s not loud, but annoying because I know it’s there, the only time it’s really audible is in quiet passages of movie or tv playback! Luckily the music side of the amp is unaffected.

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Well, I have unplugged each component attached to the av receiver individually, and still the hum remains. At a total loss, the only way it stops, is if I unplug the chord c line rca that connects the Marantz to the Naim.