Yamaha Digital Piano Problems

[Narkis Eatman]

Digitalpianos and keyboards are usually sturdy instruments that will provide years of joy and entertainment if properly maintained. But there are occasions when things go wrong and you must get it repaired. The most common problems with digital pianos are:

In many cases, the repairs are fairly simple in nature, and can be completed quickly. However, remember that pianos are delicate by nature, and by applying too much pressure trying to fix it yourself could actually do more damage than good. If you bend or break a contact beyond repair, a new contact board will be required. And if the new part is no longer available, it could mean having to purchase a new instrument instead.

You could fix it. It's 2 sponge / foam rails on top and bottom, all along the keyboard range. Just replace both of them. They dampen the sound of the keys being played down, and the key-return up. That is just how part of the "mechanism" works on entry digital pianos.

I did all the work needed on the floor: lots of space. I definitely used this video:

The Simple Repair of a Yamaha Clavinova to reduce Keyboard Noise at least once.

Also check out the comments there.

While playing, I noticed that some tones that I play forte / fortissimo do not sound as expected, but quieter and more muffled, as if I had only played mezzo forte or even mezzopiano. This does not refer to specific individual keys, but can occur with all keys. At first I didn't think anything of it, but it became more and more annoying to me.

Today I tested it very systematically: I played several keys fortissimo one after the other. For example, the first two notes played sound as one would expect - but the ln the third key is much more muffled and quieter, so as I would have only played it mf. If I then play this key one or two more times, even with very high intensity, it only stays with mf instead of f / ff. If I now take a short break and start again, then the key that has just caused problems and did not want to be louder reacts normally as f / ff. If I then repeat the whole thing again with other keys, the next few keys sound again quite normally ff and suddenly dull / mf again.

I wanted to take a closer look at the MIDI outputs of the keys and connected the NU1X to my laptop with Pianoteq. The program allows me to see the MIDI output (between 0 and 127; the higher the louder) of the keys being played. And then I could observe the following: When I play a key f / ff the MIDI output is around 110-120. If, however, suddenly there is one key that is quieter, the MIDI output is much lower, at around 70, as if it were limited by the software. Since the sensors work with every key, and this problem can occur with every key, I assume a software-related problem.

Before the firmware update 2.10, the NU1X was affected with the so-called "loud note issue", where sometimes very loud notes suddenly appeared while playing. Examples of this can be found on youtube or forum.pianoworld. The cause of the problem was probably due to the fact that the NU1X only uses one key movement sensor, which does not work as precisely as three-sensor systems. The problem does not occur with the N1X / 2 / 3X or with the Kawai NV-5/10 with three (Kawai two) sensors incl. hammer sensor. After the problem was first denied by Yamaha, the "loud note issue" was "fixed" with the firmware update - apparently a kind of algorithm was added to the software to detect very loud MIDI velocities and reduce them to avoid the sudden occurrence of loud notes... I guess this mechanism contributes to the fact that the software in the Yamaha sometimes recognizes very high MIDI sensor velocities as "loud notes" and reduces them, which explains the sudden duller tones. Again: The problem does not relate to certain individual keys, which could then be assumed to be a fundamental fault in the sensor or the like, but affects all equally (or not).

Today I visited the next big piano store in Berlin to test if this happens with their NU1X - it does! It seems to be a systematic error due to the "loud note issue" firmware-update "fix". The software/algorithm seems to detect intentional hard strikes sometimes (and way too often) as an unintentional "loud note" and lessen the MIDI-value, resulting in a too soft sound... But it's a false alarm. I can't believe it, how can Yamaha still produce and sell these pianos with this systematic error due to their non-sufficient one sensor system? And I can't believe how nobody has noticed this until now? It's less noticeable than a sudden out of place loud note of course, so for Yamaha this may seem to be a better "solution" than the loud note issue.

Good for you and thank you for sharing this fault for others to be aware of. Hopefully, Yamaha will be motivated to address this issue as more noise is made (pardon the pun) by owners and potential buyers.

It is not pertinent to compare hybrid numbers of sensors with usual digital piano action. Alpha pianos has only 2 sensors (hammer pressure, damper), the N1X only 2 sensors (key position, hammer strike).

I don't have a nu1x so I will fire up some ideas just for troubeshooting: your ff notes are done with fast or slow repetition? Do you think that the muffled notes occur when playing a key that has not yet completely stopped and may still be bouncing? Try to see if you find a pattern like "it occurs everytime I press a key at ff and the key is still halfway up", or "... when the key is bouncing after reaching the top". If you can pinpoint the exact conditions, maybe the engineers can fix it... But since you cannot access the sensor values (only the final midi output) your hands are tied. Alternatively, if you really pinpoint the cause, there may be an action regulation tht solves it (less/more rebound, faster/slower key reset, etc).

vagfilm Thank you! No, I didn't find with with google. I discovered the forum a few weeks ago when that ban thing at pianoworld happened. I think someone in the modartt forum mentioned it. I just didn't sign up until now.

I'm very sure it's a software/sensor issue, not a regulation issue (the action is regulated very well and even). The muffled notes also occur without repetition, for example when hitting a new, not already played note with ff intensity.

I was not saying that it was a regulation problem. I thought maybe it was a firmware problem related with the starting position of the key: if the key travel was less than expected, the firmware would translate your midi 110 into midi 70 to avoid a loud note. But if the problem can also occur at first strike, then it is as you suspect: either a sensor problem (not likely) or a consequence of the loud note safety firmware (very likely). Maybe CG has another clever idea...

vagfilm I am note sure. The NU1X was delivered with the newest 2.1 Firmware (that supposedly fixed the loud note issue). Now that I agreed with the dealer to return the NU1X I will not start to mess around with the firmware. But it really would be interesting to see if the "muffled ff note issue" (thats how I call it) disappears with the return of the "loud note issue" in an older firmware, as it would prove that this problem was introduced with the "loud note detection" algorithm in the 2.1 Firmware update.

My guess is that Yamaha is using some AI to figure out how loud to make the sound, and that this AI is not infallible. But given that there has not been much criticism of the NU1X since the (presumed) AI was included in a software upgrade, I have a feeling that Yamaha is going to ignore this issue with a vengeance.

Since the issue happens when the key has not been released fully but just below the top position, the sensing logic assumes it has been released fully and will be ready to detect a repeated strike. However mechanically the jack has not been reengaged under the butt and the key is then very easy to be pushed with a high velocity (no weight to throw under your finger) and so the sensing logic is fooled into thinking this is a regular strike with a high velocity. So, my suggestion here is that this can happen in different situations. Of course one of them is to do it deliberately as I have demonstrated:

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However it can also naturally happen in quick repetition, such as e.g. single key repetitions or trills when the key hasn't returned fully and you're pressing it again. And so for this particular case my proposal is for the sensing logic to detect the time between two or more activations of the same key (even if there is another note in between) and if one of the repeated strikes has a velocity higher than say 125 while the duration is shorter than a threshold (hence the repetition is quick), then assume this is the "loud note issue" happening, so then take the velocity from the first strike (or average it for multiple such strikes) and apply it to the "offending" one. This can work in many situations but unfortunately may affect genuinely loud strikes...

Anyway, a member on PW implemented my proposal (I forgot his name, wasn't that actually @xooorx ?) and published it on GitHub by just using a script interpreting the MIDI data, similar to @vagfilm MIDI filter. He said it was working OK for him and soon he was contacted by Yamaha and they provided him with a beta firmware that implemented the same logic for him to try. Later on they made it official and also created one for NU1 (but it's not published, people should ask Yamaha for it).

As has been discussed so many times, there's no easy solution to this problem if using only key sensors. I believe the only simple and good solution for Yamaha would be to add mechanical repetition springs as in -feurich-high-speed-kamm-upright-action

But eddiepiano stated that he could create a muffled note by a single ff stroke, without repetition. So, if this is reproducible, it is note a jack issue. My bet is that at some fffff strikes, the Yamaha logic calculates very high velocities, and as a safety measure assumes that to be a "loud note issue" and puts the note at m... (you can hear Yamaha engineer say: "no, no, no... no pianist can play this hard... if it is this high speed it should be a misreading due to repetition, and in that case make it a midi 70 and he should be happy").

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