Nord User Forum

[Moominpig]

Hi

Sorry to keep banging on about the Nord Power Supply Hum issue, but I may have a slightly different issue, so just wanting to compare it with other owners in order to figure out whether I have a defect.

I purchased a brand new Electro 5D yesterady and am noticing the power supply noise ONLY because it is manifesting as a constant sine wave-type tone, around the pitch of the G above middle C (I believe this is G4). If I put my ear next to the case, I can hear a DIFFERENT buzzing sound, which sounds more like electrical buzz to me, but at normal playing distance, I cannot hear that buzz, but I CAN hear the 'tone', even with headphones on!

The problem is that it's really quite distracting. Of course I don't hear it whilst playing, as the sound of the key mechanism alone drowns it out, but when I stop playing, all I can hear is that G4 tone playing away.

I have noticed that if I apply mild pressure with my palm to the top of the case, it does dampen the tone slightly, but doesn't completely eliminate it, so it appears to be some kind of sympathetic resonance of the case.

I'm trying to learn to live with it, as I love the keyboard otherwise, but this is really quite distracting. I could easily live with the 'buzz', as i cannot hear that at normal playing distances, but the single tone is much more intrusive and frustrating, especially as it is slightly out of tune with the G4 tone that the actual keyboard produces! I can also hear it across the room! I'm in a quiet room though!!

Can any other Electro 5D owners, or owners of similar products, confirm my experiences of an audible 'tone' at playing distances (and beyond) rather than just a 'buzz' with your ear right next to the case?

Because I bought the unit in store, I won't be covered by distance selling regs, so I'm concerned that I won't be able to get a refund or exchange on this product if Nord insist that it is perfectly normal. Not sure what to do.

Thanks

[Moominpig]

I stuck a video up here: https://youtu.be/TMc3CFgD4wQ

Admittedly it's difficult to distinguish on the video, above the noise floor of my iphone. Also, you'll have to crank the volume up, which doesn't particularly help my case

[Lee Batchelor]

Hi Moominpig,

I hear a typical transformer hum but no buzz, high frequency oscillation, or overtones.

"Because I bought the unit in store, I won't be covered by distance selling regs, so I'm concerned that I won't be able to get a refund or exchange on this product if Nord insist that it is perfectly normal. Not sure what to do."

Not sure what you mean by this, however, I would have Nord take a look at it to make sure the power transformer is not defective. As mentioned, I can hear mine while at rest in my studio, but not very well. Perhaps you could measure the incoming voltage at the receptacle the Nord is plugged into. Make sure it's within the specified voltage range for your area. I'm just guessing on that one .

- Lee

[pterm]

I ran the first 50 seconds of your youtube video's audio track through Audacity to see what's there, and yes there is definitely a peak at about 400Hz (the "Peak" window indicates G4 as you said) as shown here:


The Spectrogram (frequency content versus time) shows the 400Hz appear at the 12-13 second mark when you switch on the Nord (horizontal stripe at the 400Hz level) -- NOTE that Audacity's timescale is a second ahead of the youtube timescale since I manually cued it and didn't synchronize.


I hoped to see some intensity change in the 400Hz as you moved the camera around, but nothing obvious jumped out. It may be because of the distance of the iphone's microphones from its camera.

Since the 400Hz falls at a mulitple of the UK mains frequency (50Hz), there is a good chance that this is coming from the power supply.

There is a small chance that this is a harmonic of a voltage booster in the OLED display. If you brighten or dim the display intensity, do you notice a pitch change or intensity change in the sound?

[Lee Batchelor]

Good catch, Pterm. It would be interesting to see what the graphs look like when using a mic that has a calibration file instead of an iPhone mic, which has an unknown frequency response curve. All the same, you likely have a pretty good representation of what's going on.

[Moominpig]

Yes, nice analysis there, Pterm! Unfortunately I can no longer troubleshoot as I ended up returning the Electro at the weekend. Shout out to Andertons Music Co. in Guildford though for being very understanding on this matter and providing a full refund with absolutely no hassle. Turns out their returns policy for in-store purchases is the same as it is for online purchases, which they are by no means legally obliged to offer.

Damn my super-sensitive hearing