Piano World Home Page Forums Our Most Popular Forums Digital Pianos - Electronic Pianos - Synths & Keyboards Kawai ES520 Teardown

Full Album here: https://imgur.com/a/OWj7zqe

Based on measurements, the pivot is between 19.5cm and 19.8cm depending on the, roundness, of that end piece.

Black key, between 14.5-14.8cm

My squeaky key problem was due to the lubrication of the centering pin, the black thingy near the front, where it rubs against the internal walls of the key stick. after lubricating, the squeak was gone. I do not have any clicky noises yet. (2nd to last photo, lubricate both sides of black piece)

I standby what I said about the chassis design being poor, the speaker chamber is cast into the top housing. but the screw holes next to the reflex port are too shallow, when I went to remove them, I could tell the original assembler already stripped them. this is part of the vibration issue. the top housing is really flimsy plastic. the bottom is helped by the action bound to it, which has some metal in it, but the shell itself is equaly soft.

The pcb design and layout is good/ well thought out. the breakout boards are nice in case they need repair.

Overall, I still believe the RHC action is kawai's best action superior in speed, evenness, dynamic control.

sure, their RH3, GFC, GF may be more realistic, but they give up playability in all those areas. GFC and GF especially felt extremely uneven.

All the cabling is well thought out, no slouch here, very well done.

Serviceability is good, nothing impossible to take apart.

Interesting. Thanks for posting!

Thank you very much for the teardown pictures and the comments on the build and serviceability.

Since your comment about the action continues to be the minority opinion, and you're so hellbent on repeating it with words that leave little room or grey area, I'm curious if you would tell us how long you've been playing, whether you have a piano degree, whether you are a working keyboard player, what repertoire you've played recently, and perhaps link to a recording? Exactly how much time have you spent playing the respective actions you cite? Do you play regularly on well-regulated, newer concert acoustic pianos as a reference? I'm just trying to understand exactly where you're coming from.

Terminal Degree, I will not get into a tiff with you on he said she said, by asking for my qualifications you are engaging in a veiled attempt at personal attack to "disqualify" my opinions. That's all they are, my opinions, if you don't believe them, don't. I could tell you I'm over qualified, you'd still call me a liar.

I assure you, that is incorrect.

Perhaps you came from a background of gigging on the road as a keyboard player throughout the 1980s, playing synth actions. Or as an organ player. Or a harpsichordist with an interest in early music keyboard instruments. That would make the context of your comments make more sense, as to how you might have arrived at that conclusion.

If, instead, you've been playing for only a couple of years, then yes, you might be right that I'm sort of disqualifying your pronouncements based on a lack of real-world experience, or at least providing a more objective "check and balance" to these opinions. The internet "echo chamber effect" can be a strong one, that is sometimes based on little actual experience with a specific product.

none of the issues I've raised comparing these actions rhc/rh3/gfc/gf require virtuosic piano skills/experience to deduce.

I've said, the let off makes the keys feel uneven, because some keys had them, some keys did not, it was more pronounced on some keys, less on others. if we take a look at any letoff bumper, it's clear why this would happen, as it relies on friction and contact. as the lubricant wears down over time, the 2 parts rub with more friction, over time, this could rub an indentation into the bumper, the let off could then go missing. it is also possible that some letoff bumpers are slightly shorter or longer, over time, again leading to uneven feel. rh3/gfc/gf all exhibited this problem regarding their letoff implementation. which i've personally experience on the store models I've tested.

on the gfc/gf, I've said that they produced uneven loud notes on certain octaves when I demoed them at the store, I've also then went home, and found at modartt's forum a whole thread dedicated to this issue on the vpc1, they came to the conclusion that small differences in the geometry of the wooden key sticks and felt punchings result in these regulation issues over time.

I've tested my RHC with the same method they used, a long flat edge of wood, and my rhc had extremely perfect midi output agreement between the keys. and because it doesn't have letoff, it's also completely immune to the bumper problem.

then you go on to attack me as the minority, this is not true, just because no one articulated these issues the way I have, does not mean they don't experience them, and on an even larger scale, everyone who did not choose to buy kawai may have potentially been put off though perhaps in more obscure manner/awareness.

I am a kawai fan, my only intent in explaining these issues is so kawai can be aware and consider their engineering options in the future.

@KawaiFanboi: Thank you very much for your detailed post

Thank you for posting.

I do not know why you opened it, but It is always nteresting to see the inside of a DP, and more for me since yours is close to mine. I hope you will be able to put it back together, in a good working way.

I think it is always important to know from where someone is talking, and more when this person use arguments (opinions??) of authority. In that sense, I think you should not misunderstood the words of terminal degrees. It was not a personal attack.


In the others forums of pianoworld, people seems more educated in that sense. But here a lot of peoples put their opinions as generalities that everyone should accept. In the others forums, it seems to me that the members do not act like this. They are somehow more humble, since piano playing is time consuming, difficult and so on. Maybe it has to do with the "geek factor" of all these technologies, I don't know.

I had to open it because one of my keys started to squeak, it was because the black insert on the stabilizing pin did not have enough lubricant. it's been fixed, and put back together. I also lubricated 20 or so other keys because they were also dry-ish, not as smooth as my freshly lubed key.

Nice pics, KFB!

I had from a previous thread a claim that the RHC1 in the ES100 is 21cm. But I would guess it's the same as RHC2 and your measurements are a bit more precise (there was no ruler in the pic and maybe they just cited the full keystick length).

thanks for the tear down pics and discussion 👍👍

the LOWER side little quarter circle protrusion butts against the nylon fixture at the end is what rotates, so depending on its axis, the actual pivot position has some play, which is why I'm quoting 19.5-19.8mm,

on the es100, the length of the key isn't telling because we have to look at where it actually rotates. further disassembly would be required.

Thanks. Interesting to see the inside of a DP I like very much.

np 36251, it's an eventuality for all slabs to be taken apart, dust ingress eventually gums up the lubricant and you have to soap then relubricate.

reminder, you don't need to unbutton the inner 2 row of screws which hold the action to the bottom case. you only need to unscrew the outer ring, the 4 next to the reflex port, the cable hold, and the tiny round one in the center.

KawaFanboi, just curious, where are you located? Wasn't your ES520 covered by warranty?

Somebody's cage has been well and truly rattled and with no reason! The guy did nothing more than state his opinion based on his experience of these actions and also his requirements. He left plenty of room for the different opinions of others.

I agree with him. It's very good. I was going to add "For the money" but, to me, the money side isn't the issue.
Too, he might have implied that the more expensive actions do not justify the extra dosh; I'd agree with that too if he'd said it. But none o' this matters does it?
Others have their opinions and they'll exercise them. You'll not stop 'em, lad.

Service technicians, they're underpaid, tired and work for life sucking corporations. As I've mentioned in my OP, the screw holes near the reflex ports were already striped from the factory, this is probably because they did not change their pneumatic driver tensions between the long and short screws, to save time. or maybe a design flaw as the hole depth is too shallow. I try to diy as much as possible because it's my stuff, and I can take the time to be careful on screw tensions, to be gentle, on lifting the components, etc. if I send it out, it has to survive UPS, yet more underpaid, tired workers, on top of the service center with their deadly auto screwdrivers.

screws cut into the soft material, so if you unscrew and these are coarse threads, you have to be careful putting them back in, such that it's going into the original threads, if you just go in without looking, it can cut another groove and this hole will be much looser over time, the technician has to get the job done he's got 10 pianos lined up, he feeds his family, there's no time for him to line up screws. the chassis is flimsy enough as it is, with loose screw holes, it'd only get worse.

I played a KDP75 the other day--same action, I believe--and one thing I have to commend Kawai on is getting the grading right. The upper register is distinctly lighter than the bass. Most "graded hammer action" in others, like Roland, is practically imperceptible, with the treble keys being relatively heavy and sluggish. Yamaha isn't much better.

That said, I preferred the overall feel of Roland's PHA50. Very substantial and extremely well cushioned at the bottom. (KDP75 felt a bit hard at the bottom, like most DPs.) Lighten up those treble keys just a touch and it'd be perfect.

kpnut mentioned in the other thread that preference for touch weight is very dependent on the volume you play at. this may create a dichotomy during the buying process. you set a high volume at the store because the background noise may be higher, there may be people talking, etc. so at the store, the touch weight feels right, relative to that volume. when you get home, you don't set the volume that high, so the keys feel heavier than they should be. kawai rhc is a good balance on that front, as it's quite light, I don't play at acoustic piano volumes at home if I can help it.