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View Full Version : Things that hum, buzz, whirr and rattle....



RichB
27-08-2014, 08:06
Are a pet hate of mine. I recently asked a question on another forum in relation to a review of a balanced mains unit which, although positive in terms of the SQ improvement, also mentioned some audible noise coming from the unit. I am trying to get my head around the idea of introducing an item into the listening area to improve SQ which also makes some noise of its own. I expect that as I was referring to an item the manufacturer is currently looking to offload my comments there were perhaps seen as interfering with business. However this is an area I have a particular interest in and I might even be a little OCD about.

For me, any item which enters my listening room must be silent both in operation and at idle. That is a prerequisite. Perhaps I'm just overly picky where this is concerned but if i could elimate a source of noise in the room then I would rather than introduce one.

Some examples of steps I have taken in my own system to ensure silent operation

Case and mechanism dampening on a Marqntz CD player I own
Using a Squeezebox touch as a digital source (replacing a laptop which had fan noise)
Preferring optical connections for digital sources to reduce potential for RFI
Putting proper feet on a TiVo box to reduce the rumbling sound its internal hard drive makes when stood on a wooden cabinet.
Using high quality (Kensington) power supplies for laptops elsewhere in the home as the supplied ones created an audible ground loop when used in adjacent sockets.
Moving the large linear PSU for the squeezebox to a location as far from the turntable as possible.
Removing a cheap DVD player from the listening room as it created a whirr noise and now use chromcast for videos and movies.
Removing ornaments and such from the fireplace where my sub was causing them to rattle (most noticeable with loud movie sound effects)
Building in solid cabinets which are fixed to the wall and placed on concrete floors.

I live quite near a light passenger railway at the rear of the property, when I'm having a listening session I close the doors to the back of the house so the whoosh of the trains and the constant murmur of the central heating boiler in the kitchen can't be heard. I also replaced the old double glazing in the property with the best rated stuff I could find. This reduced traffic noise from the outside considerably.

When nothing is playing and put my ear to any the components, I can hear no buzz or transformer hum. When I play music there is only the music, when I play nothing and concentrate on work or the crossword there is a wonderful silence (from the audio components anyway, environmental noise notwithstanding).

A while ago my dear friend Mr Mad Moon of this parish brought around one of those BT mains conditioners folk seemed keen on using. We plugged it in and listened for around 30 mins before the low hum of the big traffo in the thing became too much for me and he took it away.

So, my question to the forum is.... When is an upgrade actually a downgrade? When the component itself makes a mechanical noise in it's normal operation?

Does anybody here own any bits of kit which make noises when they are used and, how do you live with them?

YNWaN
27-08-2014, 08:29
All equipment with a large transformer in it (and plenty with quite small transformers) will make some form of mechanical hum.

Many years ago, when in retail, a chap brought a cassette deck back saying it buzzed. We couldn't hear anything, put it in the very quiet dem room and still couldn't hear anything; at this point he revealed that you did have to press your ear to the case to hear it!

How do I live with it - with ease, I just put some music on.

RichB
27-08-2014, 08:49
All equipment with a large transformer in it (and plenty with quite small transformers) will make some form of mechanical hum.

Many years ago, when in retail, a chap brought a cassette deck back saying it buzzed. We couldn't hear anything, put it in the very quiet dem room and still couldn't hear anything; at this point he revealed that you did have to press your ear to the case to hear it!

How do I live with it - with ease, I just put some music on.

Yes, but that's not the level of noise I'm getting at... I'd expect that in properly cased equipment, a noise you might hear with your ear up to it would be inaudible when sat a couple of metres away. However if you could hear that noise when the music stopped playing from where you were sat would you still feel the same? It would drive me batty knowing it was there.

walpurgis
27-08-2014, 10:11
I have a DAC that has mains transformer noise, you can hear it across the room. I've checked the transformer mounting and it is solid. There is nothing fouling or touching it, but it just vibrates. I've put some small sorbothane pads between the top of the tranny and the steel equipment case and this has quietened things quite a bit (yes there's plenty of room for air to circulate). Strange thing is the noise dies down a lot once the DAC has warmed up for half an hour. Rather odd. The transformer looks solid, but I'm wondering if there's slack between the core plates.

awkwardbydesign
27-08-2014, 11:28
Does anybody here own any bits of kit which make noises when they are used and, how do you live with them?
The cat. It's purring now, I just give it a clip round the ear and it stops.
But the fridge in the kitchen drives me up the wall, even with the door shut.

Macca
27-08-2014, 11:55
I guess there is a difference between mechanical noise and noise that is actually in the signal. A hum or buzz through the speakers is the sort of thing that will drive me mad whereas a little bit of noise from, say, a cooling fan won't bother me as long as the unit is a fair distance away. In terms of the balanced mains unit referenced this does seem to produce some mechanical noise but not noise in the signal. Whether I coud live with that would depend on the level of the noise, I suppose. But there is a big difference for me anyway between that sort of noise and noise that is audible through the speakers. It is only the latter that I have no tolerance for. background noise I am not so bothered about. Just bang up the volume a bit ;)

My listening room has a pretty quiet background most of the time, less than 30dB. The only thing that ruins this is the Virgin TV box that chunters away to itself almost all the time whether it is in use or not.

Spectral Morn
27-08-2014, 12:06
Pet hate of mine too, fans, buzzing transformers etc and CD/SACD players that can't spin a disc silently :(



Regards Neil

YNWaN
27-08-2014, 12:17
Hum and buzz through the speakers is extremely low - I do have some mechanical noise from power amp transformers and fans - I don't find it a nuisance.

Ammonite Audio
27-08-2014, 14:01
The mains in my house has a clipped waveform, which does cause some transformers to buzz audibly. One of the reasons why I use a PS Audio P5 mains regenerator. As we get more and more interference on the mains, whether from outside or from within our homes, this type of noise is going to become more common.

anthonyTD
27-08-2014, 14:09
Also, if you have a piece of kit that has an audible mechanical hum/buzz you may notice that its worse certain times of the day, and its pitch/frequency will also tend to change!
A...

Barry
27-08-2014, 17:50
The mains in my house has a clipped waveform, which does cause some transformers to buzz audibly. One of the reasons why I use a PS Audio P5 mains regenerator. As we get more and more interference on the mains, whether from outside or from within our homes, this type of noise is going to become more common.

That would mean there is a DC component on the mains. It this DC component is greater than 100mV, then it will usually cause transformers to hum/buzz mechanically. Toroidal designs seem to be especially prone to this.

RichB
27-08-2014, 20:55
So its not just me then....

Macca, I also have a virgin TV box and it chunders away like nobody's business. I would be well rid of it were it not a concession to the other half who records rubbish programmes to watch when I'm not there.
I got some rubber feet on it which stopped it reverberating through a TV cabinet which seemed to amplify it.

Cats at fine though, in fact scientists have proven that the presence of a purring kitten in the listening room actually increases sound quality. Maybe that's the secret, a lovely kitty has been sealed inside the culprit equipment.

Spectral Morn
27-08-2014, 21:39
Also, if you have a piece of kit that has an audible mechanical hum/buzz you may notice that its worse certain times of the day, and its pitch/frequency will also tend to change!
A...

Yep noticed that :(


Regards Neil