Kawai VPC1 faulty key weighting (Page 4 of 4)

Thank you, YvesTh,

not at this point in time of development. I just see the midi events with a debug node coming in and leaving velocity changed. No Pianoteq connected so far, see the USB vs. 5-pin connection mismatch. Later I will test what is going on physically on the MIDI-wire with an oscilloscope. With an resistor-tap the MIDI byte voltage can be seen directly on the in- and output serial loop.

I have heard about your mentioned software in the past and that it can handle a single velocity curve. - But can it manage 88 individual velocity curves (= one per midi-note)?

Thank you, sounds like an option.

PS: Unless you have to fill 11264 values by hand ;-)
PPS: A MIDI-signal from the keyboard running through the Edirol MIDI-Interface, through the netbook with Nodered and calibrator prototype, and to Edirol midi out again takes around these times:

2.2 - 2.6 ms noteon
1.9 - 2.2 ms noteoff (noteon with velocity=0 here)
1.5 - 2.0 ms control (Pitch bend, Modulation, Data entry)

Tapped with an oscilloscope.

Hello, sorry for resuming this old topic.
I am considering buying a Kawai VPC1 (I am into Classical music, but my piano skill is still low).
Based on your experience on the problems described in this post, would you consider buying the VPC1 as a goold choice anyway ?

Are there other valid (possibly better) options roughly in the same price range or not too far  ?  (in Europe the VPC1 costs about 1300 euros/dollars)

My primary goal is to find a good quality action, to be used with virual pianos (Pianoteq or others) and headphones or external monitors, so I don't mind if there are no speakers / onboard sounds (like in the VPC1)  or they are poor quality:  I just want a nice and consistent action that is not too far from a real piano.

Thank you
MP32

Sorry for not writing any context about my current situation.
At the moment I have a very old Clavinova (CLP 840, bought in 1998 or so), which has an old style weighted keyboard,plastic slippery keys, etc....
I want to buy a new piano because my CLP 840 has several problems because of the age (2 pedals not working, very noisy keys, inconsistent key action between the different keys etc...)
I also don't like at all the boxy sound produced by the onboard speakers of the CLP 840, I never did.

I have recently "discovered" the beautiful sound of the new Virtual Pianos softwares (pianoteq, VSL and others) , and my plan would be to buy a good relatively unexpensive keyboard / DP  with a very good action and  buy some Virtual Piano software and good quality monitors.

I don't have access to real grand pianos , so I just want a step up and take advantage of the modern tecnology compared to my old CLP 840.

Thank you

MP32,

It's a shame there isn't easy access shops to try this stuff, instead of having to rely on opinions of strangers on the net.

No need to apologise about the lack of context, I thought that was useful information for a frame of reference.

I nearly mention PHA-4 too in my first post to you. I think some of the advanced pianists find the weighting slightly slow for fast trilling (all things being relative).
While it might be nice for everyone to have that ultra fast response as an option the current affordable mechanisms haven't pulled that off. 
It could be considered extremely expensive to add the subtle improvement of fast key return for an entry-level learner, or less serious amateurs. It would be lost on me most of the time I imagine.

As has been said before PHA-4 is used mostly right through the Roland range until the very top. They also use it in their top MIDI controller.

I like the action on my humble bottom of the range Casio CDP-130. I might have to get some extra usb widgets to enable extra foot pedals.
I would probably like the PHA-4 too.

I might upgrade one day to a VPC1 myself, then again this probably won't happen. Lots of other things to consider and it's not like I'm a serious classical pianist or anything so it would be quite the indulgence for me. I would like it though.

I advise you to open the keyboard and observe what creates friction on the black keys (the only critical element is the adhesive at the end of the key which can stick to the mechanics and create friction when pressing the key, the problem has been definitively resolved with the GF3 mechanics). I haven't had any mechanical problems.

The adjustments you can make with VPC Editor MIDI Offset make sense for small values, especially for keys that play slightly louder. The side effect is that you reduce the dynamics of the MIDI 1-127 velocity, you are not calibrating the keyboard but just applying an offset to the already calculated value! If you have notes that play too softly it becomes a problem, after the adjustment you won't be able to play very softly anymore!

Currently the firmware does not allow you to do the calibration. Many users change the rubber strips that appear to be causing the problem. I opted to use custom electronics to scan the 12x22 diode matrix.

Here are some internal photos of the mechanics and electronics if they help.

The first thing to do is to use the keyboard as an end user. If it performs well for your purpose then there's no need to worry. The type of virtual piano used and the musical style might mask this problem but if you are a classical pianist and if you use a sophisticated virtual instrument with 100 real sample levels (=Vienna Symphonic Library) there are many small nuances that bring out any problems of calibration.
I had calibration problems on two central octaves and I changed the rubber strips and electronics under warranty and things improved apart from the first octave A0-A1 which sounds much softer.
If it becomes difficult or not guaranteed to calibrate with the hardware components (rubber strips, ...) then it becomes relatively easier to compensate for the divergences through a new custom MIDI encoder that implements this function through the software since the Kawai firmware does not does. So official support can help you if you are lucky but it is not guaranteed to work fully.
So I repeat that if the keyboard responds well there is no reason to worry.

The keyboard is weighted differently from A0 to C8 therefore for calibration purposes it is more meaningful to play a cluster of white notes or black notes with a stiff bar to keep the pressure constant on all the keys in the cluster. The third graph has acceptable values between 95 and 105, it does not seem comparable with the other two much more unstable.

Now I see better, thanks. I too have noticed that the MIDI velocity values of the release are more accurate (=less divergent) than those of the key press. It would have been better to have the opposite!

There are some things that are subjective. I can speak from my direct experience without filters. I can't tolerate MIDI velocity divergences higher than 14 (therefore +7 or -7 with respect to neighboring keys).

I have tried all the Kawai keyboards:
RM3 Grand (MP10)
RM3 Grand II (VPC1)
GF1 (MP11/MP11SE)
GF2 (CA67)
GF3 (CA79)

GF1 is too light for classical use, better RM3 Grand and even better RM3 Grand II. GF2 is even better with a very smooth feel. I prefer GF2 to GF3, GF3 is a little grainier as if you can hear the mechanical elements moving more, someone might like it more. (You can also apply modifications to the mechanics, you have to try them). You don't have many options as a stage piano, no GF2 and no GF3 unless you take the raw action and repackage it as a stage piano.

Yamaha NW-GH3 (Natural Wood Graded Hammer) is also very good for me but it has one problem: there is a strange feeling of the key returning as if pushed by a spring.

Hey,

thank you cauldron for your personal insight of the actions, the details worth a lot to me - makes me again think the VPC1 is the best choice for my desired goal.
Lets see what Kawai will reply!

The Action got some "hook" with a flexible counterpart that causes a resistance when releasing the key, to simulate an acoustic pianos behavior at release.
I've read somewhere (I think its in this thread, check the first site) that some people deactivate this.

Because the VPCEditor wont run in my OS (works with WINE but is not recognizing the MIDI connection) I dont know if people refer for a setting that can be deactivated in the software (which I kind of doubt) or if they refer for physically removing it.

EDIT: Hahaha you were talking about the let-off simulation by yourself on the first page?

BTW:
The idea to use points instead of lines makes a lot of sense - looks way cleaner! Never considered it as I blindly followed the mass

Greetings.

Hi,
Velocity curve is not weight curve...
It is the velocity of the finger hitting the key that creates the velocity of the key and therefore the outgoing midi velocity, not the weight of the finger (your finger always has the same weight). Of course the resistance of the key slows down more or less this velocity during the key stroke and it is important that this resistance is homogeneous on the whole keyboard. However I think that it is by pressing all the keys at the same speed (with a straight edge for example) that we can highlight a bad calibration of the sensors independently of the pressing force.

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Really? Where are the three trigger points of a VPC-1 exactly?

For example in an old Kawai ES3 the time interval is taken between key depth 5 mm and 9 mm (midi off and on):

The Kawai ES3 has a double sensor. Although the Kawai VPC-1 has a triple sensor I would expect similar dimensions with just one more trigger between 5 mm and 9 mm.

EDIT:
Oh, sorry, I saw your older posting at https://forum.modartt.com/viewtopic.php...47#p983647
It looks like the time interval in a VPC-1 is taken between 8 mm and 10 mm in your photos.

Hello,
I was commenting on the article as a whole and addressing everyone and no one at the same time.
You are absolutely right about your comment. Your formula is correct without resistance but the key has a resistance and the acceleration is not going to be 9.81m/s2 during the stroke. If the key had no resistance it would sink at the same speed with any weight (light or heavy). The reality is that with a very light weight it will not sink, but with a heavier weight it will sink very fast.
However, it is the speed of the key (and its acceleration because it starts from zero speed) that creates the velocity of a midi keyboard or the velocity of the hammer in a real piano.
Another remark about keyboard actions, it seems to me that in Roland action like "Pha-4 standard" the sensors are activated by the key itself, but on VPC1 I think that the sensors are activated by the hammer (closer to real piano). With Pha-4 you have to do almost the whole stroke to have a signal, with vpc1 the hammer is thrown at the beginning of the stroke and a half stroke can product a sound I mean. What do you think about it ?

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The let-off point is exactly between sensor 2 and sensor 3, after sensor 3 there are a few millimeters of key end. The value was calculated by measuring the electrical resistance (2 MΩ) of each of the three contacts starting from the diode and with the HD74HC138P integrated circuits removed as visible below:

Sensor 1 closed

Let-off start, sensor 2 is here, just after

Sensor 3 closed

Key end