Astonishing problem?

[javibap]

I bought a Nord Piano 4 some weeks ago. Soon I noticed that, sometimes, some keys, yielded a double sound. You can hear it in the attached audio file.
I sent this file to the Nord Support Team and they asked me to check whether the problem persisted after making a MIDI loop. I did, and the problem disappeared. Then they said that the mechanical part of the keyboard should be replaced. After that, I contacted the dealer and they gently agreed in changing the whole piano for a new one. I received the new Nord Piano 4 last week and… the same problem!! It happens less frequently, yes, but it still happens.
How could it be possible?
Am I bad at using the triple-sensor mechanism? Maybe, but I have played the piano for 45 years, and have had several acoustic and digital pianos in my life. If the cause were in the way I play (how???), there should be other users noticing the same problem, and this doesn’t seem to be the case, at least in this forum.
Dust in the action mechanism? Are Nord pianos that sensitive to dust (two pianos affected by dust from the very beginning)? And again, it seems that no other user has noticed the problem while dust is everywhere.
Slight voltage or power variations in my home? But they never affected my previous digital pianos.
Nord pianos are acclaimed, and surely this is fully justified. So it is very unlikely that they made two pianos with the same problem, and that both of them ended up reaching me. Then, did the dealer simply changed the sticker with the reference number and sent me the same piano twice? Well, it is a big dealer. I don’t believe they even consider making shabby things like that. Besides, I guess this must be unfeasible somehow.
But then what? Any suggestion?

[FZiegler]

Hi, I think, it won't help: You will have to give it back again. Obviously, it isn't always the same key that produces phantom hits.

Normally, Nord has a quality control before shipping, so it shouldn't happen. The keybed, however, isn't made by Nord, only calibrated.

[Projet Xion]

Hi javibap,

Do you use sometimes your NP4 as a midi controller?
I don't have the same problem than you but I noticed that midi messages can affect durably the programs.
For example if I use the Nefertiti program with Cubase, some midi receive messages like wheel can alter the program, even after a restart of the piano.

[Hlaalu]

What do you mean? If you don't save the program, it should definitely remains as it was. "Nefertiti program" doesn't tell us much since one can name any of the Programs in any way he wants.
Which parameters exactly you think remain the same after being modified by an incoming MIDI message, even after a reboot?

[baekgaard]

What do you mean? If you don't save the program, it should definitely remains as it was. "Nefertiti program" doesn't tell us much since one can name any of the Programs in any way he wants.
Which parameters exactly you think remain the same after being modified by an incoming MIDI message, even after a reboot?

Not sure what is meant, but playing a sound based on the Nefertiti EP8 in Live mode could of course be persistent across s reboot - but I guess that is not what was meant.

As to the OP, it is unlikely to be bad power or anything like that. It sounds really strange and not like anything I've encountered or heard of before, but surely Nord support knows best how to deal with this.

Sent from my phone in brevity

[Projet Xion]

What do you mean? If you don't save the program, it should definitely remains as it was. "

Nefertiti program preset by default hasn't tremolo effect.
If I play a track on Cubase with a control change message (let's say pitch bend) sometimes the effect stays even if don't save the program. In this exemple Nefertiti will keep the trem effect.

Even more weird : if I reload the original program, it will keep the previous settings. The only way to switch back to the original program is to edit it and manually removing the effect before saving.

Very strange I know but I think there's a conflict between the midi receive messages and the lack of pitch / wheel on the NP4.

[baekgaard]

What do you mean? If you don't save the program, it should definitely remains as it was. "

Nefertiti program preset by default hasn't tremolo effect.
If I play a track on Cubase with a control change message (let's say pitch bend) sometimes the effect stays even if don't save the program. In this exemple Nefertiti will keep the trem effect.

Even more weird : if I reload the original program, it will keep the previous settings. The only way to switch back to the original program is to edit it and manually removing the effect before saving.

Very strange I know but I think there's a conflict between the midi receive messages and the lack of pitch / wheel on the NP4.

The NP4 doesn't respond to pitch bend, but it does respond to the control pedal / expression (cc11). In fact, if enabled, it will modulate the extent of the effect.

So if you play with a tremolo effect and send it a low cc11 value, the tremolo will disappear. If you send it a high value, there will be a lot of tremolo.

When you press play, Cubase will send out the current controller settings. Even if you reboot your NP4, it will of course sound the same when it gets the same set of controls -- which may also switch on the effect, if you send it the right CC.

So what you describe sounds like it may just do exactly as described in the manual

[javibap]

Thank you.
Of course I will give it back again, FZiegler. And not, Project Xion, I didn't use my NP4 as a MIDI controller, not yet. However, I simultaneously recorded the audio I have attached as a MIDI code and, when I sent it back to the NP4, the sound was good, no doble-notes. So, it seems, the problem is in the keybed.

[Hlaalu]

Do all the keys do this or just some of them?

[lawman]

Hi, javibap,
On my Nord Grand, I sometimes experience the double sound that you describe. It only happens, however, when I'm playing very, very softly - in fact, as softly as I possibly can on this instrument.
Occasionally, when I'm playing very, very softly, my light attack is almost counterbalanced by the return mechanism, causing a slight key-bounce and a doubled note. Here is a video demonstrating this phenomenon (first I play a few notes at mezzo forte, then as softly as possible):
Could your technique be causing this behavior, as mine sometimes does? Does anyone think that my NG is defective because of this?
Two last things: First, I have never experienced this phenomenon with any acoustic piano or my previous Nord Piano 3 or Piano 4. Also, you might note that this issue was discussed previously, in a 05/23/2020 post by jchau.
Hope this helps.