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I'm in the market for a new digital piano.

I purchased a Kawai CN34 four years ago and have used it somewhat regularly since then. However, a few months ago, I started to notice that some of the keys were not very responsive (it took a lot more force to generate a sound than for other keys). From my local Yamaha dealer, I learned that often keys fail because they employ a pressure-sensing technology (using pads), and sooner or later, the sensor pads fail.

Currently, I'm considering primarily the Kawai CS11 and the Yamaha CLP-685 as replacements, although I'm open to other options.

The Yamaha dealer mentioned that the CLP-685 uses optical sensors to identify when and how to play a sound. I called a Kawai dealer to identify the type of sensors used in the Kawai CS11, but they could not give me an answer. Based on my experience with the Kawai CN34, there's no way I'm going to elect to purchase a piano that uses the pressure-sensing technology--I don't want to be right back here in a few years.

So my question: does anyone know what technology the Kawai CS11 uses to sense that a key has been pressed?

Also, any feedback on the CS11 vs. the CLP-685 or any others that might be in the same ballpark?

Thanks for any info you can give.

I don't know about the claim regarding the CLP-685, but the CS11 has the Grand Feel II action, which does not have optical sensors.

Neither CLP685 nor CS11 utilize optical sensors. 100% sure about the latter. And 99.99% about the former but since nobody ever took a picture of it, there’s some slight chance of Yamaha overachieving themselves and putting optical sensors without mentioning about that in marketing materials. Maybe in another galaxy or rather universe.

Can anyone confirm whether there are any other digital pianos in that price range that use optical sensors?

The only piano with optical sensors in that range is Yamaha NU1X. It uses upright piano action and has optical sensors under the keys but not on the hammers. Due to that, there is a known “phenomenon” with the piano that you can hit or not, depending on your piano technique. The other digital pianos with optical sensors are Yamaha AvantGrand and Kawai Novus NV10.

There's a picture on this page where you can see the velocity sensors. There are definitely not optical sensors in any of the Yamaha or Kawai straight DPs; they are used only in the hybrids.

EDIT: btw, it's worth checking the warranty. It varies around the world, but in some places Kawai offer a 5-year warranty as standard, and in that case they could replace worn pressure sensors under warranty.

Karvala, which picture are you referring to? I can't find it...

Like CyberGene mentioned above, the closest one is Yamaha NU1X.
Optical sensor is usually found on hybrid digital piano or acoustic with silent system (there's also silent system using contact sensor) or player piano (with recording function).
Hybrid pianos like Kawai NV10 and Yamaha AvantGrand use optical sensor but it will cost "slightly" more $
But it is possible a digital piano with that price range to have optical sensor on its pedal, like on Kawai GrandFeel pedal.
you might also consider acoustic upright piano with silent system




Also check out someone's post about CLP685...
https://forum.pianoworld.com/ubbthre...cs-of-grandtouch-action.html#Post2734488

LOL, sorry about that, I had the official Yamaha page and the recent photo breakdown page open, and copied the wrong one without noticing! I've fixed the link now. It's the same one that has been posted elsewhere in the forum.

Is my experience fairly typical with a piano having pressure sensors? Or did I just get a dud?

I don't have stats to tell me what is typical. I only have one piano.

It has had four octave-long contact strips replaced. One strip was bad ... the octave surrounding middle A. The G key was a dud.
I also replaced three nearby strips. They had not failed yet. But, because they, too, were in the most-played center region of the piano it seemed prudent to replace them.

That was when the piano was about seven years old.

As for your earlier post ...Only a few of the top-end, most expensive pianos use optical sensors. The rest use rubber contact pads.

Is the optical-sensing technology that much more expensive to produce than the pressure sensors? Or is this merely another instance of designed obsolescence?

I believe the Lachnit MIDI controllers also use optical sensors (with a modified Fatar action).

http://www.flkeys.at/home.html

Kind regards,
James
x

Which image of the Chinese post are you referring to specifically, though?

Kind regards,
James
x

As a matter of fact those are not pressure sensors. Instead they use 2 or 3 binary switches in succession and the velocity is derived from the duration between the switches activations. Which is what they also do with optical sensors, so the basic principle is the same.

More an optical sensor note for CyberGene's custom piano project (can't remember name of his dedicated thread):

The uber-expensive Lachnit portable slab appears to use the very expensive Vishay TCUT1300 optical sensors (about 1$ each in bulk); see very clear video of one sensor in action in video below:

https://youtu.be/O2kNZAoORrw?t=14s
http://www.vishay.com/docs/84756/tcut1300.pdf

Lachnit's opto sensor operation summary / marketing pitch:

http://www.flkeys.at/FLKFaqEng.html

Not sure if the following quote is true, but seems like an obvious & clever programming item to consider if you are designing a built-in velocity curve on your project: "I was told, the "Dynamics knob" somehow changes the velocity curve but there is NO loss in MIDI range. It's always from 0 to 127. And supposedly only Lachnit keyboards/ midicontrolers have that.''

http://www.forum-pianoteq.com/viewtopic.php?id=3042

Here's a GH3 diagram, which gives you a good sense of where the (non-optical) contact sensors are:


Here's a different angle from NWX, which you can see the curved hinge of the hammer where it strikes the rubber caps:


Note that the contact sensors are the diagonally-positioned board at the right of the image--it slants up facing the front of the keys.

Now here's the image from the new GrandTouch:


While you can't say for certain from this angle, it sure looks like it is looking down the top of the keys into the same mechanism with the same type of pcb. Plus, I'm also of the opinion that if Yamaha moved to non-contact optical sensors, we'd be hearing a lot more about it from them. Though, TBF, they could have also mentioned that GrandTouch has offset pivots for the black keys and they declined to do that too. They've actually be cryptically silent about the nature of the new action...

I know all Vishay optical sensors by heart already And that particular has been on my radar. The thing is I can’t come up with clever way of using it with the hammers since it also requires some patterns. My next step is creating a wooden enclosure with a stop rail for the hammers. And BTW I decided to position the CNY70 sensors close to the hammer pivots (similar to AG and Novus). All’s in my head only I don’t have any time to go work with a wood cutter Having a baby really sucks all the time one has...

Congrats Evgeny! I know exactly what you mean, I'm on pat leave right now as well.

TONS of time for little stuff, ZERO time for anything big

Thanks, but she’s almost 9 months now, just to clear any confusion I mean I started a crazy DIY project after she was born which is the reason why my wife thinks I have a mid-age crisis

P.S. Ohh, congrats to you too!