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I just purchased a Kawai VPC-1. I love the touch, but the most obvious problem is that the keys have very uneven response. First, each octave from A to the G# above seems to be doing its own thing... some octaves are less sensitive (quieter), some are more sensitive ... by quite a lot. Like the same touch will produce MP in one octave and nearly F in another. There are also some odd keys here and there which differ from their octave.

I see that Kawai provides an individual key sensitivity editor in the software download. What's the deal? Are they basically admitting that their quality control is horrifically uneven and it's necessary to calibrate every keyboard, key by key? Anyway the editor is not sufficient because it provides merely a static offset, whereas the whole key curve needs to be calibrated (i.e. an offset would affect P more than F, which is not necessarily what the situation needs).

What is the deal?

Maybe I'm not reading your post right, but would you please specify what software you're using together with your VPC-1? VPC-1 is NOT a standalone digital piano, it needs a software to produce any sound...

If you're using Pianoteq (as suggested byt the "individual key sensitivity" part of the second paragraph), do you mean, that when you press keys lightly in different octaves, the response lands in a different velocity bin? Couldn't this be a result of the different hammer weights?

Fun fact: recently, a pianist came to my house and played my VPC-1 paired with Pianoteq and I pointed out to him that his white/black key trill is not even (black key sounded louder). He claimed that it's the piano's fault. It is possibe it might be the pianist's fault (thought he might know better than me, being a pianist, he probably has an access to concert grand pianos with action with "standard" response?). I have no clue how to test this scientifically, mainly due to the black keys having a different length, pivot point being slightly further behind the fallboard, etc, so the question itself is: are black keys putting the same amount of resistance as the white keys at the same distance from the fallboard? Or is the resistance the same if measured at the end of the keys (which would be troubling: usually, if you play a black key, you tend to play the nearest white key at the same position measured from the fallboard, not at the end of the said white key)...note that the perceived loudness of a key might be the result of its resistance: if your finger plays a key with a certain amount of force and you move to the next one (from white to black for example) and it puts up a different amount of resistance, it might sound louder/softer...

The individual key sensitivity is adjustable in the VPCEditor software provided by Kawai. Have you not used it?

As it turns out I'm using Pianoteq but I'm not adjusting sensitivity there.

I'm going by ear, not looking at MIDI velocity. I'm playing a chromatic scale with decently even pressure/weight in my fingers, and some ocatves (A to G#) are much louder than others. I mean MUCH. This is beyond anything that would be uneven playing. And it's not correlated to register on the piano. Some low octaves are loud, some soft. Also the fact that the sensitivity always changes right at A is suggestive of something other than graduated hammer weights and certainly rules out unevenness in my playing.

Note: when I say the octave is louder, then I presume the VPC is generating a higher MIDI number which leads to a greater volume from Pianoteq. I never had this problem on any other keyboard using the exact same Pianoteq configuration, which rules out Pianoteq configuration issues.

Never had this problem with the VPC1. I think its really a problem of your VPC. You should contact KAWAI.

Mine was pretty even - it had a few hot keys that needed a bit of adjustment but for the most part is was nicely playable right out of the box.
I would start with a factory reset and then contact Kawai or the dealer if that does not fix it.

Factory reset instructions:

If the VPC1 is using firmware v1.04 or above (verified and updated using the VPC Editor software), a factory reset can be performed with the following steps (while the VPC1 is turned on):
1. Press and hold the power button.
2. Press the bottommost (bass end) three white keys simultaneously.

Factory reset is a good idea Morton
Mike Mey: is it a new one from a Kawai dealer or a 2nd hand?

As you can see on many pictures the pivot points of black and white keys are not in line. They are shifted parallel as well as the keys are arranged. http://www.kawaivpc.com/en/features/

Ah! That's interesting, I haven't used it, as my VPC behaves normally...maybe I'll give it another look, but I don't want to mess up with it too much

It really might be a good idea to contact the seller to resolve this issue with unevenness...



I'm well aware of this, but how is the distance between adjacent balance pins related to the difference between the end of a white key and the end of a black key? Also (and this is also true for acoustic pianos), if hammer weights are not adjusted (as hammer weight is related to what string we hit), placing a balance pin further behind the fallboard renders the effect of a hammer "lighter", so the overall feel of the key should be lighter (this also depends on the counterweights placed in the keys, but there's a difference between static weight and dynamic weight). So my question still stays, perhaps reiterated as follows: what is the quota on the weight of two adjacent white and black keys? Should they compare at their respective ends, or at the same point (i.e. at the end of the black key, which is NOT the end of the adjacent white keys)? Or is the pivot in both cases so far away, that we basically shouldn't care too much about where we measure the weight of the key, it is roughly the same?

Thanks, Morton. But I find that curious... there's a big difference between a product that has all the keys with even response right out of the box, and one that has a few hot keys. I mean that's an entirely different quality control proposition. A lot of companies would fire their QC engineer if they thought it was okay to tolerate products like that.

But it sounds like you're saying Kawai expects that? That's a big deal, to know if that's true.

Mike

New from Kawai dealer

Due to the complexity of the action, it is not suprising that some keys go out of alignment during the long trip from Asia.

To me that doesn't explain why much of the variation is within octaves (defined as A to G#). That is, each octave has its own sensitivity. Every key within the octave is similar, but the variation is from octave to octave. That sounds like either a physical issue that was manufactured right into it, or a software issue. I still need to try the factory reset.

The VPC1 is graded, right? I wonder if the grading is by "zone" (e.g. one of four zones) or by "octave"?

As I mentioned above, there's not a progression from low to high. The extra sensitive octaves are scattered randomly. There are jarring changes from G# to A in some places. Not anything that could be a normal design.

I was wondering if "by design," the grading was divided by zone or divided by octave. Not referring to how yours turned out, but about the VPC1 design. Because if the grading is by octave, there might be something wrong with your particular VPC1 associated with the way it is graded. But if it is graded by zone, I don't see why that mechanism would be associated with each of your octaves being different.

I see your point. Perhaps at the factory they produce sets of keys, A to G# above, in several hammer weights and sensitivities. Then they choose the least sensitive for the bottom octave, the 2nd least sensitive for the next ocatave up , and so on up to the top which has the most sensitive. Perhaps mine was assembled in random order by mistake. That would fit with the fact that A is the bottom note. I think we're onto something!

Not sure if it helps, but the VPC-1 has a "Pianoteq" mode which may help some with your key response issues. There is some kind of button combination you need to press (including power cycling the piano). I also found this on another forum:

No I don’t believe this is normal - it does sound like your unit is defective but a reset is always with a shot when electronic devices misbehave is all I mean.

Cheers

If VPC-1 uses contact strips similar to ES-8, then they are one octave wide and they go from A to G#. Maybe there is an issue with some strips. I would start with factory resetting as suggested anyway.

Another thing I would do is checking the velocity MIDI commands sent when neighbor keys are pressed (e.g. F/G/A/B).

This is unacceptable from the manufacturer and they simply have to either replace or fix the unit totally free of charge. I had my acoustic grand piano shipped overseas in its original crate from the factory and the action worked perfectly on arrival. And any grand piano action is a lot more complex than any DP one. In any case, it is to the manufacturer to ensure that the brand new product you bought from them works flawlessly.

As a side note, about the black and white keys velocity response discrepancy mentioned by Chopin Acolyte, it is a rather common problem in DPs, often linked with faulty hardware (components, design, etc.). I remember owning such a digital instrument and having to design a solution myself as the manufacturer refused to even acknowledge it existed. Needless to say, I never bought from that (quite well-known) manufacturer again.