Toroidal Power supply help

[Blacksabbath25]

My new Yamaha A-S3000 seems to make a low hum or where you can hear the power going though the Toroidal Power supply

I can only hear this sound when I am not playing any music and the room is quite is this normal for this type of power supply as I can’t remember the abrahamsen 2up doing it which also had a Toroidal power supply but as this was a long time ago I can’t remember if this was normal .

ive checked for ground loops and unplugged all of the connections to see if the hum goes but it doesn’t

And this hum sound that is coming from the amplifier is not past though my speakers so I am pretty sure this is normal for a Toroidal Power supply to do this .

obviously I could check the screws or bolt that’s holding the power supply as sometimes the power supply can be a little lose .

 

[Electro]

My new Yamaha A-S3000 seems to make a low hum or where you can hear the power going though the Toroidal Power supply

I can only hear this sound when I am not playing any music and the room is quite is this normal for this type of power supply as I can’t remember the abrahamsen 2up doing it which also had a Toroidal power supply but as this was a long time ago I can’t remember if this was normal .

ive checked for ground loops and unplugged all of the connections to see if the hum goes but it doesn’t

And this hum sound that is coming from the amplifier is not past though my speakers so I am pretty sure this is normal for a Toroidal Power supply to do this .

obviously I could check the screws or bolt that’s holding the power supply as sometimes the power supply can be a little lose .

Yes it's quite normal with large Toroidal transformers, my monoblocks have a low level 50hz hum that can be heard if very close to them.

I can be caused by a bit of DC on the mains, DC blockers can be quite expensive but I will try some at a later date to see if it gets rid of it.

 

[Blacksabbath25]

My new Yamaha A-S3000 seems to make a low hum or where you can hear the power going though the Toroidal Power supply

I can only hear this sound when I am not playing any music and the room is quite is this normal for this type of power supply as I can’t remember the abrahamsen 2up doing it which also had a Toroidal power supply but as this was a long time ago I can’t remember if this was normal .

ive checked for ground loops and unplugged all of the connections to see if the hum goes but it doesn’t

And this hum sound that is coming from the amplifier is not past though my speakers so I am pretty sure this is normal for a Toroidal Power supply to do this .

obviously I could check the screws or bolt that’s holding the power supply as sometimes the power supply can be a little lose .

Yes it's quite normal with large Toroidal transformers, my monoblocks have a low level 50hz hum that can be heard if very close to them.

I can be caused by a bit of DC on the mains, DC blockers can be quite expensive but I will try some at a later date to see if it gets rid of it.

that’s great thanks I thought there was a problem for a minute as my Yamaha A-S2100 uses a different kind of power supply it’s totally silent and been some time since I’ve own a amplifier that has a Toroidal Power supply in it .

and I can only hear the very low noise when I go up to the amplifier or it’s totally quiet

 

[QuestForThe13thNote]

Ive not had it as I think I said, but be careful taking the back off units to tighten screws as if you open units up you could void the warranty. Just take to a dealer if you’ve concerns.

 

[hybridauth_Facebook_100004211376004]

My nait xs hummed like a bee occasionally lol.....

 

[CnoEvil]

My nait xs hummed like a bee occasionally lol.....

Bees don't Hum...they Buzz...unless flying backwards, or in a good mood. *crazy*

 

[Blacksabbath25]

Ive not had it as I think I said, but be careful taking the back off units to tighten screws as if you open units up you could void the warranty. Just take to a dealer if you’ve concerns.

it’s only 3 screws and the top lid just slides off Yamaha would never no I’ve looked anyway i am happy now I know it’s normal for this type of power supply to hum quietly .

 

[davedotco]

Ive not had it as I think I said, but be careful taking the back off units to tighten screws as if you open units up you could void the warranty. Just take to a dealer if you’ve concerns.

it’s only 3 screws and the top lid just slides off Yamaha would never no I’ve looked anyway i am happy now I know it’s normal for this type of power supply to hum quietly .

But it is quite common. Heavy duty casework can act as a sounding board and make things worse.

As a dealer we had to deal with this on occasion, in most cases we simply swapped the unit as it was variable between samples and locations.

The best explanation that we could come up with was that dc (see post above) or a badly distorted waveform was the issue.

I recall an instance of a rack of Crown amplifiers buzzing very badly in a well known west end studio, these had large 1KVA frame transformers not toroids and the noise could clearly be heard at the mixing position. We carted the whole rack out to the then distributers, a fair trek as they were out in suffolk somewhere where we found that in a quiet rural setting, all the amplifiers were perfectly silent.

From this we deduced that it was a mains problem which I think was sorted with the use of large isolating transformers.

One occasion where some mains 'conditioning' was of very definite benefit.

 

[insider9]

My nait xs hummed like a bee occasionally lol.....

Bees don't Hum...they Buzz...unless flying backwards, or in a good mood. *crazy*

Hahaha excellent *lol*

 

[Blacksabbath25]

Ive not had it as I think I said, but be careful taking the back off units to tighten screws as if you open units up you could void the warranty. Just take to a dealer if you’ve concerns.

it’s only 3 screws and the top lid just slides off Yamaha would never no I’ve looked anyway i am happy now I know it’s normal for this type of power supply to hum quietly .

But it is quite common. Heavy duty casework can act as a sounding board and make things worse.

As a dealer we had to deal with this on occasion, in most cases we simply swapped the unit as it was variable between samples and locations.

The best explanation that we could come up with was that dc (see post above) or a badly distorted waveform was the issue.

I recall an instance of a rack of Crown amplifiers buzzing very badly in a well known west end studio, these had large 1KVA frame transformers not toroids and the noise could clearly be heard at the mixing position. We carted the whole rack out to the then distributers, a fair trek as they were out in suffolk somewhere where we found that in a quiet rural setting, all the amplifiers were perfectly silent.

From this we deduced that it was a mains problem which I think was sorted with the use of large isolating transformers.

One occasion where some mains 'conditioning' was of very definite benefit.

the Yamaha A-S3000 has a copper chassis that sits inside the main body of main unit which the power supply sits on this copper chassis so it’s separate unit in a unit .

 

[BigH]

Be interesting to see if mains conditioner will do anything to reduce it.

Naim were renowned for humming, they got so fed up with the complaints, they told people to put them in cupboards.

 

[davedotco]

These are just more things that can resonate to 'amplify' a mechanical vibration, as I said, a sound board.

If you could take the toroid out of the amp and place it on say, a foam pad, I doubt you would hear anything.

One trick, back in the day was that you could 'tune' the big tranformers in some Naim products by adjusting the tightness of the big bolt through the centre of the toroid that held it in place. Not approved of course but it did solve the problem for us on a number of occasions.

 

[Andrewjvt]

I don't want to cause you concern but I wouldn't except it.
My Hegel h360 had a large 1000va Toroidal Transformer and was completely silent.
Some amps do have a little noise and say it's normal but it would annoy me personally so I'd check with Yamaha.

My monolith sub had a hum a few weeks ago and I brought a new power chord from bk with a filter in and it's much quieter now.

 

[Deleted member 108165]

I'm with Andrew on this, it shouldn't be happening on a flagship £4K amp. However, you have had problems with your electricity supply before so maybe worth investigating this aspect first.

 

[radiorog]

I went through several noisy rega brio r amps, and returned at least one noisy Roksan due to the transformers. Each unit made a slightly different noise. For me it's now something I listen for when looking at a new amp. When I went to hear someones abrahamsen amp, I put my ear to it, and was very surprised that it was totally silent. It depends how loud is annoying form you. My current k3 has a slight him, but you cannot hear it a few feet away. It's very quiet compared to others in have had.

 

[Andrewjvt]

I went through several noisy rega brio r amps, and returned at least one noisy Roksan due to the transformers. Each unit made a slightly different noise. For me it's now something I listen for when looking at a new amp. When I went to hear someones abrahamsen amp, I put my ear to it, and was very surprised that it was totally silent. It depends how loud is annoying form you. My current k3 has a slight him, but you cannot hear it a few feet away. It's very quiet compared to others in have had.

Totally silent
I'd recommend benchmark or hegel

 

[Blacksabbath25]

I will phone Yamaha tech support again to find out but no noise is transferred though my speakers it’s just a quiet hum when the room is quite but like I say the Yamaha A-S2100 was silent but that uses a E transformer

 

[ellisdj]

I have had loads of amps in the last year and most have had some hum mate.

Its annoying but not the end of the world

Also if I come to your to do a power conditioner demo I have a DC blocker you can try as well

 

[Blacksabbath25]

I have had loads of amps in the last year and most have had some hum mate.

Its annoying but not the end of the world

Also if I come to your to do a power conditioner demo I have a DC blocker you can try as well

it’s doesn’t matter that much as it’s not been transferred though my speakers and if it did I would no that’s not right but as I’ve said it’s only a quiet hum of power going though the power supply when you next to the amplifier or the room is quite .

i did check the screws this morning that hold down the power supply to see if there was any lose but they are completely tight so no issues there .

yes that would be great to try a DC blocker to see if the noise goes but will check this morning with Yamaha to find out about the hum just to rest my mind

 

[ellisdj]

I will be honest I havent found it to stop the hum

 

[ellisdj]

Could be why I am a big advocate of certain isolation products - if its humming its vibrating - humming loudy enough to hear = lot of vibration - something to think about

 

[Electro]

To be honest every piece of equipment I have ever come across with a reasonable sized toroid inside has mechanical hum to a certain degree.

In my system there are 8 toroids and they all sing together ( 50hz ) with one voice along with every other electrical piece of equipment with that sort of power supply in the house they all vibrate in unison so it may be several other pieces of equipment adding to the overal noise, but it is still only audible in a very quiet room usually at night.

In my monoblocks the toroids are mounted vertically on the tall front panel encased in thick aluminium oblong boxes that might amplify the hum slightly but it is really not a problem at all, in fact the Virgin media box especially with it's hard drive grinding away is often noisier !

No noise of any kind comes from my speakers ---- apart from music of course.*smile*

 

[Electro]

Could be why I am a big advocate of certain isolation products - if its humming its vibrating - humming loudy enough to hear = lot of vibration - something to think about

As you know I use Isotek Titan and Nova conditioners but they make zero difference to the 50hz hum, but they don't block DC.

I have an old Lynwood 1500 va isolation transformer knocking about so I might try that on one monoblock to see if it goes away or reduces it, but the irony is that even isolation transformers hum a bit. *unknw*

 

[ellisdj]

I meant isolation products that sit under the kit and that drain vibraton - stillpoints etc

 

[Electro]

I meant isolation products that sit under the kit and that drain vibraton - stillpoints etc

Ahh I see, that might be worth a try , the very slight noise really isn't a problem for me but I would like to get rid of it if it turns out to be DC on the mains.