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Brand new Piano 5. I can hear the power supply buzzing.

Posted: 22 Sep 2021, 21:29
by dcjams
Hi

Brand new Nord Piano 5 bought in the UK. Arrived with damaged box. Retailer insisted it would be fine and that it was just packaging.

Second day of use I can hear the internal power supply buzzng/humming.

You can't hear it over conversation or passing traffic but in a quiet room it's clearly audible.

It's loud enough that I can capture it on my iPhone.

Is this normal?

I'm hoping the answer is no ...

Thanks
Jim

Re: Brand new Piano 5. I can hear the power supply buzzing.

Posted: 22 Sep 2021, 23:07
by pterm
Hi Jim,
Unfortunately, this is common.
When people on the forum raise this issue, they typically describe it as having been quiet at first but after some time they notice it humming.
Nord uses a transformer in their power supplies. They buy a transformer encased in an epoxy-filled plastic case to minimize the humming. The transformer core changes shape due to magnetostriction, so eventually this loosens the epoxy and increases the hum.
It seems possible that the shock that damaged the box accelerated this process, so you could take this up with your retailer and possibly enjoy a period of relatively quieter operation if they replace the unit. Based on reports on this forum, eventually the humming appears, so expect that eventuality.
-pterm

Re: Brand new Piano 5. I can hear the power supply buzzing.

Posted: 22 Sep 2021, 23:23
by dcjams
Sure, thanks

But one wouldn't expect it from a brand new instrument? It's two days old! Or can they leave the factory like that?

Re: Brand new Piano 5. I can hear the power supply buzzing.

Posted: 22 Sep 2021, 23:45
by FZiegler
Maybe it's the power supply, maybe it's the OLED.

post141568.html?hilit=buzz#p141568

Re: Brand new Piano 5. I can hear the power supply buzzing.

Posted: 22 Sep 2021, 23:46
by dcjams
FZiegler wrote:Maybe it's the power supply, maybe it's the OLED.

post141568.html?hilit=buzz#p141568
Yes that occurred to me also. I remember back in the day things like sampler screens getting noisy inverters.

Re: Brand new Piano 5. I can hear the power supply buzzing.

Posted: 22 Sep 2021, 23:53
by dcjams
FZiegler wrote:Maybe it's the power supply, maybe it's the OLED.

post141568.html?hilit=buzz#p141568
Oh I missed your link in my first reply. Not OLED on that basis.

I've just noticed that if I push the power lead downwards towards its socket the hum is reduced.

Re: Brand new Piano 5. I can hear the power supply buzzing.

Posted: 23 Sep 2021, 00:27
by cgrafx
There are two components that make audible buzzing sounds.

1. The transformer in the power supply.
2. The inverter circuit on the OLED screen.

Both of those sources of audible noise are common, although a high-quality properly-wound and potted transformer really shouldn't make any audible noise. Personally I think that should be part of the Nord design spec for the transformers and they shouldn't pass quality control if they buzz, but it doesn't affect the functionality of the keyboard so clearly not part of the design spec for those parts.

The noise in the OLED inverter circuit on the other hand is a byproduct of the design of the DC-DC voltage converters used in the OLED screens and I don't believe there is anything that can be done about that.

Re: Brand new Piano 5. I can hear the power supply buzzing.

Posted: 23 Sep 2021, 00:33
by dcjams
cgrafx wrote:There are two components that make audible buzzing sounds.

1. The transformer in the power supply.
2. The inverter circuit on the OLED screen.

Both of those sources of audible noise are common, although a high-quality properly-wound and potted transformer really shouldn't make any audible noise. Personally I think that should be part of the Nord design spec for the transformers and they shouldn't pass quality control if they buzz, but it doesn't affect the functionality of the keyboard so clearly not part of the design spec for those parts.

The noise in the OLED inverter circuit on the other hand is a byproduct of the design of the DC-DC voltage converters used in the OLED screens and I don't believe there is anything that can be done about that.
I love it otherwise, it's amazing, but I need to decide if it's a deal breaker for me. Is there a chance another unit would be silent? I'm still within distance selling rights to return without reason. I didn't know Nords can suffer this issue. I find it hugely dsitracting. I've gone to sit on the other side of the room to read or something and I can hear it. My intention was for an instrument for my quiet, gentle home which I go to great lengths to keep peaceful. I use open-back headphones too and I can even hear it when wearing those! I've plenty of other music gear and none of that hums.

Ho-hum. Disappointed :(

Re: Brand new Piano 5. I can hear the power supply buzzing.

Posted: 23 Sep 2021, 00:34
by dcjams
dcjams wrote:Ho-hum. Disappointed :(
Haha! No pun intended :D

Re: Brand new Piano 5. I can hear the power supply buzzing.

Posted: 23 Sep 2021, 00:37
by dcjams
The kicker is by the time I'm likely to know whether I'd get used to the buzz or not it'll be too late to return it.