Black boxes are ringing

I´ve noticed the black boxes are ringing quite loud. It´s a sound I can excite either with my voice or with clapping my hands. It has got me thinking that this resonance must be excited when playing music. Anyone else noticed this? And how does it affect the listening experience? At the moment I am working on the room to get it as good as possible and this ringing could be part of some of the sonic problems I am experiencing. I find it hard to understand what is ”wrong” when something doesn´t feel quite right. I can´t easily pinpoint and be certain it´s a problem related to this or that.

I now put my little wooden bird on the pre and a wooden brush on the poweramp. The ringing is now gone when hand clapping. I´ll have a listen and see if there is a difference in listening experience.

By the way I ruined my wall and moved some panels to the first reflection points in the ceiling😁

Yes, this has been covered and discussed here on a few previous occasions. It seems that the outer cases are like an energy sink, which is perhaps why they tend to sound and perform best when used on a rack with similar principles, i.e. providing a direct energy path to ground. The flip side is that thanks to the decoupled (or even suspended) boards within, it does tend to mean the electronics within are unaffected.

What’s most interesting is that back in the old days Naim provided a sliding damper on the back of the case which would stop the ringing. Only trouble was that generally performance was preferred with the damper not engaged…


That´s very interesting. I tried to stop the ringing on my 202. I don´t remember what I was using but prefered the performance without whatever I put on top. As I remember it, it kind of killed the music.

The racks you are refering to do they transport the ringing down through the rack in some way? I have isoblue but have no clue how they work😁

IIRC, many years back there was a bit of a fad Stateside for placing an NHL ice hockey puck on top of the case. I guess that, as far as these tweeks go, it was a cheap one with which to experiment…

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Yes, if you look at racks like the Fraim and similar, they are more about channelling energy than isolating or absorbing.

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Thank you Richard!

My 250DR sometimes hums a little. Yes, I’m talking about a humming transformer, rather than a ringing case, and as Naim amps go, it’s not very loud at all. The rack sits right next to the sofa, and if the amp hums, I can stop it by gently pressing the top of the case with a finger. So presumably the casing is, perhaps unsurprisingly, soaking up the internal vibrations and resonating. I can’t say I’ve noticed any of this affecting sound quality, but as long as the system is sounding good, I won’t be sweating over it too much.

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So does mine. The 200dr I had before was dead quiet.

So you did!!

You must be popular at home!!

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Ahaha! Yeah. I live alone with my kids and my 11-year-old daughter wasn’t impressed.

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Subject: damper

The damper has been fitted to most of the large case equipment for at least the last 15 years, if your pinging equipment doesn’t have one for some reason, please call or e-mail.

To stop the pinging, just slide the damper up so that it touches the top.


Date: February 22, 1999 02:37 AM
Author: julian vereker
Subject: connection

If one mechanically connects the case top to the chassis with anything except the plastic extrusion fitted to most of the large case equipment, the sound is very noticably degraded, and even sliding the ‘case damper’ up, so that it makes contact with the case top and damps the ringing, affects the sound in subtle way.

Boring, but true. . .

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Recommend a DC Blocker. My NAP250DR went from rather loud buzzing to dead silent with the blocker in place. Love it!

For me, the hum is only just audible when no music is playing, so I don’t feel the need to reduce it further. Using my finger as a case damper seems to work well on the odd occasion when it seems to be audible, but we are perhaps not strictly talking about the ringing that the OP was hearing.

Thanks for the tip. I don’t really mind the gentle humming.

As I’ve read humming transformers is decreasing performance too so if so it’s not just about tolerating the mechanical hum :blush:

@Lucifer Did you continue doing any treatment to your ringing chassis? I’ve noticed my 272 ring a lot actually. If I play music and press paus I can hear the ringing continue for a second or two. That’s not super great really because that means coloration of all music played since the impulse response will be loooong… What if one have 6 Naim boxes and they all add their own ringing. Scary thought. Being obsessed with that music should sound as intentioned I need to solve this otherwise I could as well remove all room dampening, speaker stand filling etc and create a church :wink: Of course equipment should not ring. That’s just protecting bad design. Right now I have put a record weight on top that killed the ringing. Might stick with that.

Yes there was!

And I remember an old Naim US piece from Chris K saying that a CD case worked well (and back in the olive days it did).

Anyone else remember the Shun Mook Mpingo discs? Quite possibly the biggest load of BS I’ve ever heard in hifi.

Nah, I had let it be. I noticed the same as you though. Ringing whb music stops, but not for long. Maybe my room treatments kills it.

Your room treatment won’t understand what is chassi reverberation and what is music so no, it won’t I’m afraid :blush: It will color your music but if you prefer that then up to you of course :+1: Spending this money on getting the sound right and then the equipment ring like crazy is not an option to me, my ears or my beliefs in what music reproduction is about.