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Hello,

I have the Kawai NV5 and I am having continuous problems with the sustain pedal. Simply this: when you take the sustain "off" then the notes keep sounding. Not all the notes, but certainly enough to adequately demonstrate the problem. This has happened twice before in about 15 months and now it is appearing again. The technician from Kawai has come and done some adjustments and it has worked fine afterwards, but after some months the problem re occurs. It's on a 10 year warranty and I've had it about 16 months. So do I call the technician out for the next 8-9 years every 6 months or ask for a replacement piano? Does anyone else in the forum have this problem with the NV5 or is it just me!

Thanks and best regards,
John Dean

so you're not talking about the undamped section of the last 2 octaves right ?

No, these are all the notes of the piano.

I think ..... the first step is to ask the warranty tech why it is happening again in just six months or so. The warranty department will have the case logged ..... so you will be covered.

Are you sure you aren't pressing the sostenuto pedal (the middle one) accidentally? It's literally impossible that the damper pedal affects only a bunch of notes.

Hi there, yes, I have the NV5 and have the exact same problem, I had a technician about a year ago and the problem has also resurfaced I have a technician booked for this Monday, it is worrying as it seems like the sort of thing that will keep reoccurring and I need to find out how to fix it myself once the warranty finishes 5 year warranty for me with 3 years to go , it really takes the joy out of playing it as you cannot control the piano everything of course sounds 'mushy'

So, first the problem doesn't exist, then it starts happening and keeps happening and after a technicial visits it stays away for a while?

Something mechanical slowly gets misaligned?

We have some photos of the damper mechanism somewhere on this forum. Must be one of the previous NV5 topics. There's of course the pedal box, a push rod and apparently something borrowed from other Kawai digital then sensing the push rod movement. Some adjustment bolt moves? Some felt compresses? I have no idea and no NV5 to study myself.

Maybe the technician could show what's the temporary cure on the next visit?

It happened before, and was fixed by a hardware ajdustment by the tech? As tyr mentioned, this is odd. If possible, it may help to have a video demonstrating it.
While the NV5 has a real damper back action, I don't think it is connected to anything tone-generating. The damper pedal depresses a microswitch or optical gradient sensor that triggers the holistic damper effect. There isn't an easy mechanism that would explain how that would result in a sustain of some notes but not others unless it's a software issue.

take some pictures of the mechanism.

With respect due to anyone, it seems pretty clear from the OP (and seconded by another member ) it is possible.

It might be more impossible to happen on an AP but definitely less impossible to happen on any breed of DP.

Well certainly it's happening, but I think what we're saying is that it sounds like a novel issue. Unless we're just satisfied as a forum to say "go away and ask your tech," it's worth mentioning that it is odd from an electronics/mechanical perspective (which the NV5 has both of) and more information would be helpful. I don't think anyone is calling OP a liar or a fool.

Thanks for all the replies. It's a relief to know that someone else has exactly the same problem. I'll get back to the shop and tell them the situation and I suppose that I could ask for a replacement NV5 as it seems that the problem cannot be fixed.

Given that another poster is having the same problem, are you sure you want another NV5 and not a different piano? I think Kawai should give you the choice of an NV5s or a CA99 with a refund of the difference in cost in the latter case.

Certainly extra details are needed. For example, is there absolute certainty that it occurs only for some notes - but not 'all' of the notes? And --- this is assuming you're playing something just fine (with pedal and all) ----- and the issue then surfaces say after 5 minutes, or 15 minutes, or even half an hour ------ when everything was fine up to that point?

Also - this is assuming that the instrument has had time to initialise when powering-on ----- as in nobody is pressing any keys, or pushing a pedal etc during the powering up and initialisation period.

It's believable if the sustain event gets stuck (as in a release instruction not getting through due to hardware or software issue), applying to all relevant keys. But occurring only for particular notes could be a bit questionable. Although, hopefully - by chance - if the issue occurs during a midi recording (that's if it has midi recording), then that will be excellent. As the data can then be analysed - and hopefully can see what's going on in there.

Sorry, no. The damper mechanism is pure cosmetic. The pedal rod is pressing exactly one sensor to to make a note sustain, regardless which note is played. It's the other way around. it can happen with acoustics rather than digitals. I bet something triggers the sostenuto switch in any way.

it has to be optical or a pot to support half damper.

I'd say, the first step to actually diagnose this, is to connect a computer to the MIDI port. Dump the MIDI messages while the problem happens.

Do the MIDI messages show the pedal as "down", while the notes are sustained? Even if the pedal is physically "up"? If the sound is consistent with what the MIDI messages say, then we're looking at a mechanical / sensor problem. The pedal is in one state, but the pedal unit signals a different state.

On the other hand we might observe the MIDI messages always to correctly follow the pedal state, yet hear sustained notes that dont match the state. In this case, we're looking at an electronics problem. It could be the connections between the boards (unplug and re-plug all connectors, check if cables are severed near fasteners). Or it could be a faulty board (slightly bend/flex the boards while reproducing the problem to see if that changes anything).

Another diagnostic test would be to use the internal MIDI recorder. Record while reproducing the problem, then play it back. Does this sound wrong, too? Does it sound wrong in EXACTLY the same way, or is it DIFFERENT every time you replay it? The latter (different) would again point to an electronics problem with the sound generator and sample memory. It's important to do this test with the MIDI recorder, not WAV or MP3.

This is actually a very good thought, it would explain everything.

The NV5 has very audible microswitches on the sostenuto pedal. OP should be able to hear it "click" if this happening on his piano, and he could check if the "randomly" sustained notes actually follow the sostenuto pattern.

check if it's a sealed switch, maybe dust from floor / socks are getting in the switch causing chatter.

+1, +1, +1 . . .

To read the MIDI events, use Pianoteq's "MIDI event" window, or a DAW (Reaper is free for testing), or maybe MIDI-OX. I'm sure there are other alternatives.