Chord Qutest/Super Nait 3 buzzing through speakers (and SN2 too)

Bear with me for a second here…

So my SN3 came back from fixing, and trying it out with a chord dac, noticed something strange:

  • When nothing attached to the amp, no buzzing|
  • Using a Chord Dac into the amp say, into the CD input, I hear buzzing through the speakers no matter what input is selected. The Chord Dac is hooked into the CD input only for this experiment.
  • When I hook up my NDX into say the streaming input, and still have the chord Dac attached - … No buzzing!

So the mere fact that I’ve got a Naim source attached to the integrated fixes the buzzing.

I sort of had the same issue with a Naim SN2 many years ago - except that I could hear the buzzing when I moved the volume knob to top volume without any source, but that buzzing would go away when I attached the naim source.

So - Given that I think this is by design, and the units are not defective, what do you think is causing this? Some gremlins in my electric system?

Adding the NDX provides a signal earth to mains earth connection. Set the NDX earth switch to floating and the buzz will come back.

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So - instead of the psu that came with the chord unit, I hooked it to a cheap apple type PSU that came with my schiit dac and it’s provided usb cable. buzzing gone. Tried with the psu that comes with an iPhone - also no buzzing.

But tried with the smallish 5V/3A PSU that I had at home - buzzing back.

Hmmm Strange…

These don’t do the signal earth to mains earth, I’m sure.

And in other news - the $100 schiit Modi sounds as good as the $2000 Chord Qutest - with supernait 3 and my Totem Kin Minis.

The Modi 3 ($100) is good value. I’ve owned one, it was good but the Modi Multibit ($250) was better (less clinical, more “musical”, earthy and holographic). Fed from a really good SPDIF source I thought the Modi Multibit the equal, or better, than my Linn Akurate Katalyst DS/3 ($10,000?) so the Linn was sold. I thought the Schiit Bifrost 2 ($700) was better again by a fair margin compared to the Modi Multibit but compared to the nDAC the Bifrost 2 was (surprising to me) easily beaten.

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You’re right that these won’t provide that ground connection but may have different levels of leakage current. Is the NDX normally in the system ?

How are you attaching the Qutest to the SN3 / SN2?

If you connect via RCA (both ends) I believe you may well experience some ground loop hum. However, when I used a HiLine with an adapter to RCA on the end into the Qutest, no hum at all.

That said, I used a Anker 20100 power bank to power the Qutest. Lowered the noise floor and lasts about 30hrs of use. I would disconnect it at night and charge it for the next days use. It also cuts out any hiss at all, even if the volume dial is on full…no music playing of course!

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sort of between systems at the moment. Had a Nac72/HiCapDR/250DR. Bought a SN3, sold off the Nac72. SN3 broke, sent to distributor. Got a good deal on a 282 (while the 250 would just not sell). So bought the 282. Now Naim kind enough to send me back a brand new SN3…
So - will either sell off the sn3 or the 282/250. Or keep both… But can’t spend another 10K on a source for the SN3, so the chord qutest must do.

Must say though - Naim has hit the ball out of the park with the SN3 - I could easily live with it instead of the 282/250 system. And the chord qutest is embarrassingly close to the NDX2 - but just isn’t a Naim.

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I would really like to understand this better though - the same qutest with ‘faulty PSU’ plugged into a Non-Naim (actually $500 Rega IO) does not exhibit this behavior.

The Rega IO is again a strange beast - it’s IEC is not grounded. !??! - so that took care of the grounding issue. wtf?

I have had the same with a dacmagic psu. I have 3 dacmagic and thought one had developed a fault, buzzing throught the amp. I moved the dacs from system to sytem and the buzzing only occured in the one room. Bger I thought the amp has a fault. Then I tried the psu swap. The buzzing moved with the psu change. I managed to find an alternative replacement as CA didn’t have any in stock. That buzzed, back to square one. Then finally the CA one turned up. That cured the buzzing. I still haven’t wotked it out but I can only assume an earth loop, or lack of earth problem.

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I had the very same with 5si and anything I connect to it - a streamer, a subwoofer, etc. I hooked the grounding from the socked and connected it to the external RCA connector of the amp and buzzing gone.
However, when I connected nd5xs2, no buzzing even without grounding.

This is an old thread, but Richard has kindly re-opened it for me.

It seems that my new Qutest and SN3 are suffering the same issue - a system reorganisation mean that I disconnected CD and FC (connected to the amp only via a Blue Heaven DIN lead) and the mains buzz from hell erupted.

All my mains inputs are filtered, so the source of the noise must be the Chord Qutest, but reading through this thread, I note that others have no issues with the DAC plugged into other devices? Has there been any resolution or solution that others have shared?

In the interim the Qutest is powered from a large USB power block, but is this a Naim issue? Can an external earth be connected to TT earth connector on the amp?

Sorry Pauel, just seen you post - so you have used an old RCA lead and connected it to the ground on the power socket?

I had the same issue when I had the Qutest and SN3. The issue for me was with the Qutest’s power supply. Swapping it out for a mobile phone charger completely solved the issue!
If you have a mobile phone charger at hand, I recommend giving it a go.

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Thanks for this! I’m using a Power block to do the same thing and I have contacted Chord support to flag it with them, but it seems there may need to be a fix at both ends, as other equipment seems to be able to induce hum into these amps too.

Yes, I connected the external(not both!) lead of the RCA connector to the ground on the power socked and attached this to some of the inputs of my 5si.
Actually, there are some photos of such a solution on this forum. I’ve just fixed my own instance :slight_smile:
So, if the wall socket has the proper ground, you can apply the double grounding which removes the buzzing.

In the past with other makes of kit I have made a common ground by connecting the metal cases or chassis together. Would this work here?

It does not work in my case. The only solution that worked for me was to connect the ground to the RCA input.
I can’t understand why other brands do not use any grounding. It is not rocket science.

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I was trying to find the photos - do you have a link to the forum post?

In the process of searching, I found this thread which makes some sense, except that without a second Naim component (beside my amp), there appears to be no signal earth point? Adding the CD player appears to provide this.

https://community.naimaudio.com/t/naim-earthing-update-please-clarify/