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Stage piano key action and static touchweights


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Interesting to see those Fatar tp40 actions so high up on that weight table.

 

Until this year, I used a 1990s Studiologic controller (SL 990 pro) that had a tp40 of some type--though obviously it could have been changed over the decades. I always thought it was a very lightweight action, I had no problem playing synth on it. I'm using a Moxf8 right now--GHS action-- and it feels more sluggish by a good bit. I'm getting used to it but it doesn't feel as good, it's a compromise that I made for value (obviously has sounds that, when I gig again, may come in handy!) Perhaps there's more than weight involved (?).

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Am I the only one who thinks the use of static weights misses about 99% of the point? A piano (or other keyboard) key is an object in motion, and as such has properties such as inertia and momentum. A static weight doesn't really capture those aspects.

 

To put it into perspective: imagine three key actions, made of wood, alumin(i)um, and lead. Each is engineered to require (say) 93 grams of "weight" (I know, strictly that should read "just over 0.9 Newtons"). Using the static weight method, these actions would all score identically. But they would feel completely different to the touch.

 

We can take this further. A decent piano-style action involves accelerating a freely-falling hammer about an axis, and the relative mass of that hammer and its radius from the axis will also affect the feel of the action, despite potentially identical static weighting.

 

Cheers, Mike.

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Am I the only one who thinks the use of static weights misses about 99% of the point? A piano (or other keyboard) key is an object in motion, and as such has properties such as inertia and momentum. A static weight doesn't really capture those aspects.
I would have agreed with you a year ago; but I recently saw an excellent Documentary (Amazon Prime, not free) about a piano restoration that included adjusting the action by use of static weights. So it's probably valid, even if not comprehensive.

-Tom Williams

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PC4-7, PX-5S, AX-Edge, PC361

 

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Am I the only one who thinks the use of static weights misses about 99% of the point? A piano (or other keyboard) key is an object in motion, and as such has properties such as inertia and momentum. A static weight doesn't really capture those aspects.

 

To put it into perspective: imagine three key actions, made of wood, alumin(i)um, and lead. Each is engineered to require (say) 93 grams of "weight" (I know, strictly that should read "just over 0.9 Newtons"). Using the static weight method, these actions would all score identically. But they would feel completely different to the touch.

 

We can take this further. A decent piano-style action involves accelerating a freely-falling hammer about an axis, and the relative mass of that hammer and its radius from the axis will also affect the feel of the action, despite potentially identical static weighting.

 

Cheers, Mike.

 

You and me too, brother!

 

I posted this a week or so ago in another, much less appropriate thread than this. So I'm reposting it here. I think we're saying more or less exactly the same thing!

 

Maybe it's just me, but all this recent testing of keyboard actions with weights seems misplaced, or at best, incomplete. It seems to me it's not just about the minimum weight required to depress a key. It's the resistance a key gives when pressed at velocity.

 

Think of a volleyball and a bowling ball sitting side by side on a floor. The bowling ball is clearly much heavier. Yet to get either ball moving very slowly along the floor would seem to take a similar amount of force. But if asked to propel each ball as fast as possible against the far wall, it would be far easier to flick the volleyball than it would the bowling ball. Put another way, if I were to attach a spring scale to each ball, I think I should be able to get each ball moving with minimal displacement of the spring. However if I were to yank hard on the spring, wouldn't the bowling ball measure a much greater resistance?

 

To me, moving the balls slowly seems equivalent to depressing keys with weights. Flicking the balls at velocity seems more equivalent to actually playing the keys. Are these not two different measurements?

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I agree that while weights are part of it, it's not all of it. I wish some of our piano tech friends were around to pipe in. I can't remember ATM how all those things fit together as it's been a while since I did any of that stuff myself.

 

I was also bugged by the use of the word "keybed" in that SW video, but that's one of those Battles I Won't Win. :idk:

"I'm so crazy, I don't know this is impossible! Hoo hoo!" - Daffy Duck

 

"The good news is that once you start piano you never have to worry about getting laid again. More time to practice!" - MOI

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... it's not just about the minimum weight required to depress a key. It's the resistance a key gives when pressed at velocity ... Think of a volleyball and a bowling ball sitting side by side on a floor. The bowling ball is clearly much heavier ...

Your example will work better (physics pun intended) if you make the two balls the same material, where one ball is solid to the core and the other is hollow inside. If put them on the slope of a hill, the solid ball will be more efficient at converting it"s mass into kinetic motion - meaning it will accelerate faster than the hollow ball.

 

In terms of piano actions, the hollow ball is more like a hammer/pendulum and the solid ball is more like a piano key.

 

The question is, which one gives us the feeling that we have more control? Do we feel like we have more control over the mass when it"s evenly distributed across a lever? Or do we feel like we have more control over the mass when it"s concentrated, like at the end of a hammer/pendulum?

 

And when a manufacturer says their keys are weighted - do they mean the weight is distributed evenly across the lever or do they mean they"ve added weights, so the key is acting more like a pendulum? (that"s a rhetorical question).

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  • 7 months later...

Whew!

 

Was trying to research the Kurzweil PC4 action. came across this, wow alot to think about.

 

I currently own the Casio PX350, PX560 and Fusion 8HD (yeah!) now here is the interesting part. After playing Steinways, the old weighted Ensoniqs, Kurzweils (Fatar tp10 in case yer wondering) and studying so many new workstations, a few years ago decided to go the Casio route-I can't afford a 4000 dollar workstation etc. so opted for the 350, then the 560. In terms of acoustic, not mechanical realism, I was very impressed with the tri-sensor action of the Casios, and the keys were pretty nice mechanically, but yes on the noisy side-largely due to the plastic cases I discovered, and modified, spent many hours re-engineering these boards (more acoustic damping inside, beefier cushions under the keys etc.

 

Then-contemplating one of the more expensive boards-maybe a Montage, a Dexibell, Nord etc and after much angst, I decided to sample an old Fusion 8HD, which needed some restoration. What a surprise-with all the updates from the Fusion user groups, even though this is basically a dual layer sensor keybed-I was shocked at how playable this keybed was. I am an old-school player who needed to adapt to both acoustic pianos and Hammonds. I could not understand how his keyboard could be this comfortable to play in such an old workstation-I can do classical repertoire, but run some pretty fast organ runs on it too, until I dissected my 8HD's (I now have 2 restored) and discovered-this is a Fatar TP40 weighted board-from 2005. Looking at the mechanicals-I did not much has changed in 15 years, except there is a graded version now and wood key version.

 

One more puzzle I solved-next life I will stick with a more simple instrument to work with-maybe a concert harp......my 2 8HDs DO NOT have the same keybed, but they are both TP40's!!!!! One has the black/white imbalanced dynamic response, the other does not. HOW IS THIS POSSIBLE YOU MIGHT ASK???? I did. Despite coming from the same factory, and only a few months apart (I checked serial numbers, labels and took out both assemblies completely.......the one with he balanced action has....2 different hammers. Not kidding.Tthe hammers on the black keys are designed differently from the white. And the one that is whacked-same hammers all across. And to make this even worse---the one with 2 different hammers-has tiny return springs under the pivot points, and the other one doesn't have any return springs at all. In the same keyboard. From the same factory. Months apart in assembly. No wonder the Fusion failed. And I can't feel the difference in response from one to the other-except the dismal mismatch between black and white keys in the whacked TP40-roughly 20 levels of velocity difference. The Fusions also used the TP20-same as in the QS8, and apparently did not have this velocity schmeg.

 

I've repaired many keyboards, pianos etc. I've never seen anything like this. Sigh. Posting in case anybody else-think about it. Fatar is still putting the TP40 in many of your 2000-4000 workstations. I believe I've read elsewhere-apparently this problem has not totally gone away-15 years later. And thanks for this tremendous amount of technical work on this.

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  • 4 months later...

All stage pianos seem to be based upon a keyboard trying to simulate an acoustic grand piano action. An acoustic upright has a very different action from a grand. I was trained on an upright, the school had uprights and even now in my sixties only have played a couple of old, bad treated, cheap grands.

 

The action on any piano varies wildly with quality of craftmanship, price, age, lack of regulation, bad environments etc. Additonally each players differs, some are highly classical trained some selftaught, some play many hours per day, others weeks between.

 

In the end it"s up to yourself. I have a Schimmel upright, a Kawai MP11, had a Yamaha CP4 and a friend has a CP5. Fun to play all of them, but all feel different. I think you have to play your alternatives and simply choose the action you find most pleasing unrelated to static touchweight, length of pivot, graded, ungraded. Anyway you will adapt to most actions even the ones considered to be bad.

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even though this is basically a dual layer sensor keybed-I was shocked at how playable this keybed was. I am an old-school player who needed to adapt to both acoustic pianos and Hammonds. I could not understand how his keyboard could be this comfortable to play in such an old workstation

There are relatively few times when a 3-sensor action is truly more playable than a 2-sensor action... other variables are much more significant, and it is certainly very possible to have a great-playing 2-senosr board or a terrible-playing 3-sensor one. And old doesn't mean less playable, either. In fact, Yamaha, Roland, and Casio have all made actions in the past that I think are better than anything they are making today (at least in their portable boards). Part of this can be subjective. Some of it could involve attempts at cost reduction and/or weight reduction. Some of it could be because manufacturers used to use lead and they don't use it anymore.

 

my 2 8HDs DO NOT have the same keybed, but they are both TP40's!!!!! One has the black/white imbalanced dynamic response, the other does not. HOW IS THIS POSSIBLE YOU MIGHT ASK???? I did. Despite coming from the same factory, and only a few months apart (I checked serial numbers, labels and took out both assemblies completely.......the one with he balanced action has....2 different hammers. Not kidding.Tthe hammers on the black keys are designed differently from the white. And the one that is whacked-same hammers all across. And to make this even worse---the one with 2 different hammers-has tiny return springs under the pivot points, and the other one doesn't have any return springs at all. In the same keyboard. From the same factory. Months apart in assembly.

Also check this thread...

 

https://forums.musicplayer.com/ubbthreads.php/topics/3095101/is-fatar-tp40l-supposed-to-have-3-4-graded-spring-zones

 

Quality control has long been an area where Numa keyboards have gotten knocked. Numa is the division of Fatar that sells finished instruments available to consumers, whereas Fatar actions are sold only to manufacturers... it would not be surprising if significant QC issues arise there as well, we just don't see it as much because we aren't the customers. There has been discussion here in the past about how Nord supposedly "customizes" their Fatar actions rather than supplying them stock as they get them, but nobody knows exactly what it is Nord is doing. Maybe they are merely making them more consistent from unit to unit by filtering out and fixing the crap ones. ;-)

Maybe this is the best place for a shameless plug! Our now not-so-new new video at https://youtu.be/3ZRC3b4p4EI is a 40 minute adaptation of T. S. Eliot's "Prufrock" - check it out! And hopefully I'll have something new here this year. ;-)

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  • 2 months later...

This thread has helped me a lot so far on choosing keybeds. So after owning some keyboards I 've made my measurements following the OP ideas(and I 've a really good picture and first hand experience what these boards are all about). So I think I can add them if somebody cares about such things. I don't think action measurements really say a lot about an action feel, but they give an idea.

 

 

M- AUDIO HAMMER 88

 

 

After owning the Hammer 88 for 6 months I aggree on the OP measurements.

 

Downgeight: 73g - 71g throughout the keybed. Upweight: 47g.

 

A really good and pro grade piano controller. The problem with the Hammer 88 action is the space between the keys. It's quite narrow. Especially if the player's fingers are not thin. But in general it's not bad at all - especially if we take under consideration that it's a cheap Medeli action. And it's a cheap keyboard anyways. The newer model has the newer triple sensor Medeli action. It feels identical.

 

 

KAWAI MP6

 

 

I own the Kawai MP6 for 3 months. Really good action. Quite wide space between keys. Even better than the MP7 for piano duties (doesn't matter that it's a double sensor one). A bit heavier, otherwise very similar. Not good as an organ at all. The electric pianos are the highlight of this board.

 

Downweight measurements: Lower side 92g, Mid Side 80g, Higher Side 74g. Upweight 47g all over the keybed.

 

 

 

KAWAI MP 7

 

 

The last Kawai model on that plastic MP series is the MP7 and it has a triple sensor action. Otherwise it's very very similar action to the MP6 one (virtually the same) BUT instead of the very bass side, they 've placed a lower mid side in its place and they've extended the higher side towards the middle and added an even lighter higher side, if that makes sense. (I own the service manual for both MP 6 - MP 7 so this is something official).

 

The Downweight measurements should start around 88g and finish around 70g. The Upweight should be around 45-47g

 

It's made with the all-around player in mind (really good for organs too), that's why it's lighter.

MP7 SE has exactly the same action. The only difference between MP 7 SE and the original model is only 3 newer and better sampled piano

 

 

 

KAWAI MP11

 

 

Now I'm the owner of an original MP11 for about 2 months. The best PIANO action I 've ever played on a digital board. Great for pianos (acoustic and electric). Nothing else for this wooden action. Quite lighter than the VPC 1 (which has the same action as the MP10). That's why some classical piano players prefer the heavier VPC 1- MP 10 one. A bit limiting as a midi controller comparing to MP 6 - MP 7 but really capable at this end as well.

 

The MP11 action has 4 different sides. Downweight measurements : Lower side 90g, Low mid side 86, High Mid Side 78, Higher Side 71g. Upweight measurement: 42g throughout the keybed.

 

MP 11 action feels fantastically comparing to the excellent action of MP 6 (and MP 7) because it keeps the same weight all along the length of the long key. The space between the keys is not as wide as the MP6. But it's very very well balanced so even with fatter fingers it works greatly. The differences between MP 11 SE and the original model is 3 newer and better sampled pianos and a better optical (active) triple pedal.

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A few other observations-I am not too interested in detailed weighing and measuring-technique to me is partially learning to overcome variations or limitations in an instrument-although the more I have had to play, the less tolerant I am of an instrument tryingen trying to accomplish to cripple me. Most digitals-as many of you have described do not have the escapement mechanism which I find very difficult to deal with when trying to execute difficult expressive passages-and the other surprise-getting my hands back on a few acoustics lately-how much easier it is to play these-the uprights are so forgiving, I almost couldn't play at first, the adjustment was that great. I think the most noticeable difference for me at least-when comparing to a good grand-is the key throw-and the escapement-like playing into a pillow compared to any digital I've played for forte, fortissimo work. So the newest heavier digitals that are now including an escapement mechanism-but not for gigging work! There's the compromise, moving back to any digital. The keys bottoming out on all these-like hitting my fingers on a wooden plank and my wrists if I'm not careful with technique-will be ruined. I could play for hours on a Steinway-but even my newer digitals-can only take so much before I begin to hurt. Boogie, stride, full fisted jazz Errol Garner, McCoy Tyner style-can't do for much more than 1/2 hour or so at a time on any digital. and the reason the Casios (I guess others lightweight) are this way-are using "engineering plastic" in the keyframes holding the keys. I've removed the key assemblies (notice I carefully avoided use of "keybed") on the TP40 Fusions and the Casio 560.350/575's. the difference in weight is the keyframe. Steel in the TP40, plastic in the Casios. which is better? I feel more comfortable wacking on the TP40 rather than the Casios, and my old Ensoniqs/Kurzweils, but it might be more in my head than hands, only time and wear will tell.
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Add to this-the Korg SP-500 is the Fatar TP40 graded hammer action. So the so-called Korg "RH-2" action is...a Fatar TP40 graded action. Guess I'll have to get some weights and start measuring.

 

This key assembly is identical to one of my Fusion 8HD's-in that it has the pink colored pivot points, and 2 different colored fulcrum arms-to account for the 2 different throwweights from black to white keys-and it works well, no discrepancy between black and white keys. The only problem-not aftertouch equipped on the Korg-the Fusion is, and this old Korg sampled piano is pretty nasty-close but no cigar-what a shame I really wanted to add this to my collection-such a beautiful design, good simple operating system but except for the drumkits, many of the other sounds are either just passable or really crappy. And its a "closed" board-no editing at all, not even an EQ setting, pretty dumb but I wasn't expecting much. I think this was the "prosumer" model Triton back when, meant for mostly auto-arranging and playing piano. The auto-arrangements although I don't use these for what I do are actually pretty realistic given the crappy soundbanks, some good hooks, some very foul cheese on others.

 

This is the first time in auditioning thousands of sounds over the years-I found a sound, and I have no idea what it's supposed to be (!) on this. Some sort of Indian instrument-but it doesn't sound remotely like anything Indian or otherwise. A shame. But that TP40 action is definitely nice to play. Oh well.

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