Uneven keys

Animisha

I have a VPC-1, and when I first got it, my playing sounded horrendous. I came to understand that this was partly caused by the uneven keys - that is, when exerting the same force on different keys, or velocity if you will, the sounds are not equally loud.

I have tried to adjust for this, using the vpc-1 app, but acking a reliable method of striking a key with the exact same force, lacking a reliable method of measuring the sound level, and lacking a reliable method to adjust so the keys are even, this still feels uncertain. I used a pile of coins, amongst other methods.
Now my playing of course is fully adjusted to the unevenness that may be left - when practising a piece and I hear a note is too loud or too soft, I adjust my key attack.

Still, this bothers me.

My question is, is this something typical for a controller like the VPC-1? Or does this also happen with ordinary digital pianos? Also high end DP's like NV6 or better?

iternabe

I would say what you described is unique to wooden actions like the Kawai's RH3 Grand II (VPC1), and GF Compact I/II/III (MP11SE, CA-xxx). Just like acoustic actions, because of the materials used (wood, felt, etc.), these actions can be and needs to be regulated to achieve perfectly even response. The end result depends on quality control and regulation done at the factory, and service done at the owner's studio when new or after years of use.

In addition to VPC1 Editor app, Pianoteq (Standard or Pro) also has the ability to edit per note volume. However, IMO these edit should only be done AFTER the action is regulated to have the proper, consistent weight.

I have opened my MP11SE to see the action. To my untrained eye, the way to regulate the action is in many ways exactly the same as how acoustic actions are regulated at the same spot. For example:

Balance rail pins and front rail pins (metal) needs to be rust-free and polished smooth.
Balance pin can be bent to center the key laterally.
Front rail pin can be bent to correct "twist" of key top.
The felt bushing on the balance pin hole and front rail pin hole can be lubricated, widened (very slightly with the right tool), or replaced.
Paper punchings at the bottom of the balance pin can be inserted/removed to adjust key height, and at bottom of front rail pin to adjust key dip.
The teflon pad square at the far end of the key must be free of dirt/glue on the sliding surface to ensure zero friction
The metal capstan surface must also be free of rust/glue to slide freely over the teflon pad
The capstan can be turned with a wrench to adjust it height which changes the depth of key travel that triggers the sensor - this should only be done after key height and key dip are set correctly.
The hinges of the weight plate should have proper amount of grease applied on the inner surface. So should the point that make contact with the let-off nub be greased. Make sure no other parts of the weight plate have grease.

All of the above should be simple tasks for a competent acoustic piano tuner, should you be able to find that who is willing to work on your DP. Also a handy and careful repairman of common household items can do them successfully after watching some reputable YT videos on piano regulations (e.g. those by Howard Piano Industries).

I can post a few pictures later to further illustrate.

iternabe

iternabe I can post a few pictures later to further illustrate.

iternabe

As for alternatives to your VPC1, here are my thoughts.

The wooden actions, they all need regulation, at the factory, and maybe at home, too.
Higher end simplified wooden action like Vidal will most likely have more meticulous regulation at the factory than mass produced Kawai slab DPs. But you might still need service at home.
The hybrid action in NV5/6/10/12 are essentially acoustic actions. They are regulated at the factory just like any other acoustic action, therefore should be up to typical Kawai acoustic standard. But the complexity probably means it will need additional regulation after shipped to your home, which I think the first at home regulation should be for free in the service agreement between you and your dealer. After the initial regulation, you DP will not go out of tune (because of the digital nature). The change to touch can still be affected by environment, as well as wear and tear, although both will be much less due the use of composite material.
The high end plastic actions, I speculate, may have better consistency in touch due to the material and the tighter tolerance in automated manufacturing process. That being said, plastic actions lack the "feel" of wooden actions. An upgrade to your VPC1, if I were to choose, would be something like Roland's PHA-100 or PHA-50.

Animisha

Thank you both, that explains a lot. Also why I felt that the plastic keys on my rather cheap Casio were more even than the wooden ones on my VPC-1.

It would of course be so much cheaper to get a competent acoustic piano tuner to work on my VPC-1 than to buy a whole new instrument. If they really can do it.

CrisOliveira

I had to open my humble Roland piano (PHA-4 action) to try and fix some notes going fortissimo out of the blue. I wasn't able to identify the cause, but after putting it up together, the keys became terribly uneven. So I spent that whole day opening and closing my piano (I hope I've not damaged the screw holes) until I got it into a somewhat acceptable condition. Went to sleep, played it right after waking up, it seemed fine, better than the day before. However, middle octave A seemed to be a little louder than the rest. I have done some tests by recording MIDI data and looking it up and I deem the results inconclusive.

So now I can't decide whether I screwed my piano, or it's fine and the issue is my lousy playing, or it's always been like that and I only noticed it now. I was thinking about suggesting forum members to identify notes in their pianos that seem to be louder or softer than the rest and record something in MIDI so we could see whether or not there was a discrepancy, but I suppose I wouldn't find much help on that.

BTW, the fortissimo out of the blue seems to be loss of contact in the sensors for a fraction of a second, like an imperceptible stuttering at the onset of the note, which the piano reads as a new note being played really fast and loud (since velocity is determined by the time interval between each sensor). If that's correct, the solution is to fix whatever is preventing the circuit of the sensor to remain closed while the key is depressed. The sensors are identical to push buttons (actually, not identical, they ARE push buttons): you push down a rubber dome with a carbon pill underneath that will close a circuit on a board.

Animisha

CrisOliveira I had to open my humble Roland piano (PHA-4 action) to try and fix some notes going fortissimo out of the blue.

That happened with my humble Casio and it ended by them going fully silent...

KevinM

The behaviour of your VPC1 doesn't seem right to me. It just should be more even than what you are describing.

My MP11SE with its wooden keys is pretty even.

I have some problems that relate to specific virtual pianos and the settings I use where the unevenness is obvious. So I know the frustration you are experiencing.

With the VSL pianos they have adjustments for the unevenness for the response of the piano per key within the data files for the pianos to make the result of using the virtual piano more even.

I break this by using the timbre shift option within the piano settings and set its value to -1. This gives to my ears a richer sound. The unfortunate consequence is it highlights a bug in the VSL software so that the adjustments also get shifted by 1 and the wrong adjustment is used for each key. This is particularly obvious for the VC280 piano, but does also impact the Bösendorfer Imperial.

I've kept the timbre shift option set, but my own individual adjustments on the edit page for the VC280 is quite a mess to get what feels like an even response across the keyboard.

I don't know if pianoteq could have a similar bug that gets exposed if you may be doing something similar or not?
That would seem like quite the coincidence, but the experience you describe sounds so bad to me that the VPC1 could be described as defective. So I am clutching at straws that perhaps the problem is elsewhere based on my own experience.

Animisha

KevinM the experience you describe sounds so bad to me that the VPC1 could be described as defective.

I have no idea, no way of comparing...

I don't do anything similar to a timbre shift on Pianoteq. The one I use is rather basic.

iternabe

Here is a video by Howard Piano Industries on how to lubricate key bushings. You can clearly see the mechanism and method used on acoustic action can be applied exactly the same way on the wooden digital action like those in MP11SE and VPC1.

Here's another one showing how front rail pin can be adjusted.

iternabe

As I mentioned before, mechanically regulate the action to achieve equal and consistent height, weight, and friction must be done first. Software velocity editors can then be tweaked later - however they should not be used to compensate for poor mechanical regulation.

The proper tool to measure key weight (down weight and up weight) is the brass gram weights. By adding/removing various plates it can achieve 1-63g in 1g increment. It's overpriced in the US. But you may find cheaper ones on eBay. I found they cost only $8.64 in China.

https://www.howardpianoindustries.com/gram-weights-brass/?srsltid=AfmBOormt4CQ_xfcbuKAL1WmqZmfQ4RwFOEf7jwOMw9MwL9gU59LVTeS

Animisha

Wow, thank you so much iternabe!