Last tuesday my new Satin Black Kawai CA 95 arrived. It was a heck of a job to get the 87 kg piano three stairs up to my studyroom, but it stands… It’s my first Kawai. After having some difficulties with another brand digital piano (inferior samples, noisy action with clicking keys, etc) I deceided to invest some real money in a new digital piano, hopefully for the ‘rest of my live’ I realy like the Kawai CA 95: fantastic pianosamples, great action, beautiful speakersystem and nice cabinet.

But now THE PROBLEM. The same evening I noticed an annoying electric hum sound coming from the piano. It makes me think of a transformator sound. The sound can be easily heard within a radius of 1.5 meters, if it is quiet in my room. In the shop I did not noticed this electric hum, because I was listening to the sound of the pianosamples and focused my attention to the action and sound of the speakers. But now, listening in my quiet studyroom to ‘the sound of silence’ when the piano is on, there it is: a very annoying constant electric hum sound.
Ofcourse I tried to locate the source of this electric hum. When I placed me ear directly on the wooden top of the piano, I can hear this hum coming from inside. The hum seams to sound stronger in the area of the topspeakers above the soundboard. But does not seem to be directly related. Because when I connect my headphones, wich disables the speakersystem, the electric hum stays the same. It also does not respond in getting louder of softer by changing the volumeslide of the piano, the hum stays the same.

This réaly disappoints me! Now my question to other owners of the Kawai CA 95. Do you also hear an electric hum around the piano, or coming from the inside of the piano? Please press your ear flat on the topshelf of the cabinet on the left or right side, near the topspeakers, to hear if IT is there.

Ofcourse there is a two years guarantee period for this piano, but I hate the idea to have to ask again some people to help me bring down the 87 kg piano, and so on back to the shop…

Do you think that a Kawai Technician is able to solve such a problem on the spot?

Please respond….

If it were my piano I'd open it up and look inside and see if I could dampen the hum which is probably coming from the power supply.

If you don't feel like doing this yourself call the dealer and let them deal with it.

I would definately not open the DP myself, because then you will void the guarantee ...
Call your shop and discuss it with them.

Mine doesnt hum. Ive seen inside.... scary stuff....

Disappointing, I know, but don't regret buying the Kawai.

I have used my CA75 for nearly five years, at least one hour a day. I still love it and it has never given a moment's trouble. I see no reason for the CA95 to be different.

But under no circumstances should you go "inside" the instrument. There is nothing you can do there and unless you are an advanced electronic engineer, you are unlikely to recognise anything there anyway. It's under guarantee - tell the seller of the problem and let him have the opportunity of putting it right.

But under no circumstances should you go "inside" the instrument. There is nothing you can do there and unless you are an advanced electronic engineer, you are unlikely to recognise anything there anyway.

You don't have to be an advanced electronic engineer to wedge a piece of foam to reduce or remove a sympathetic vibration if that alone can solve this issue. I think most folks could easily recognize a power supply.

I once completely dismantled the interior (dash, doors) of a Jeep Wagoner to eliminate rattles. I don't hold an advanced automotive engineering degree.

You are a very courageous guy Dave. I'am not. Especially not in matters of electronics. And I agree with others, I don't want to risk my two year guarantee on this brandnew Kawai. But thanks anyway.

Thank you Wumpletoad. My main concern now is: can they repair something like this on location? I realy don't want to take the piano three stairs down to bring it to the dealer. Has anyone (in Holland) experience with the Kawai service?

Where are you in Holland?

Well, the question I think is whether it's a defect or not.

Most electrical items with a transformer have a slight hum. It is possible with damping and shielding to reduce the hum so that it's almost not noticeable.

UKPaul's response suggests, either he cannot hear an existing hum , or your CA95 is louder than some others.

That's exactly why I would like to hear if other CA 95 owners, register such a hum or not. I would be realy disappointed when a Kawai technician comes to my home and say: "well sir this is a normal electrical sound". In my opinion a costly digital piano like the CA 95 should not produce such a hum.

I live near Castricum NH.

If you lived closer I'd offer to stop by and open up the unit to see if we could dampen the transformer.

I'm just outside of Den Bosch.

Thanks Dave, but I rather waite for a certified Kawai technician. As I said, I don't want to loose my two year guarantee.

It should be mentioned, perhaps, that if you decide to try to dampen the hum of the power supply with foam that you take care not to interfere with the unit's ability to cool itself.

As others have recommended, any concerns with your piano should be discussed with the dealer from whom the instrument was purchased. If there is a problem, a qualified technician should be able to diagnose the fault and offer a solution.

Please do not attempt to open-up the instrument to fix the issue yourself.

Kind regards,
James
x

I have to agree with the OP. You paid thousands for a brand new piano, with a warranty. Let the manufacturer deal with the problem.

Thank you James.
But what is your experience in this matter?
Did you ever noticed an electric hum around
the Kawai digital piano's, or a hum that can
be heard coming from the inside of the cabinet?
I mean is this an exception or a regular fenomena?

Dutch,

It is most likely a power supply transformer is humming. Out of any 100 of the same transformers from the same production line, a number of them are going to hum. It's a physical issue, the transformer is mechanically buzzing. It has a loose layer in its' winding somewhere, more than likely. Your dealer should identify the offending 'culprit' in the piano and replace it.

All manufacturers have this issue where a few of their products(of the same model) have the hum but most don't.

Kawai James(as usual) gave the correct instructions.

No, I do not recall hearing any humming sound when play-testing the CA95.

Again, if I was in your position I would contact the dealer to explain the situation.

Kind regards,
James
x

I own a CA95 and there is no hum noise ! So you should get yours replaced or fixed ; )

I would suggest to search for the source first, could turn out to be something very simple in the end (acoustic resonance, power supply that touches something and when separated/isolated the hum is gone). If your can't find , or fix it yourself - have someone take a look at it - must be an easy fixable problem and I would be very surprised if the whole unit needs to be replaced just for the hum noise. Especially if the rest of the DP is totally to our liking - keep it and have it fixed.

Spend $4000 on a defective unit, and then have to fix it yourself? Not me. That's what the warranty is for.

Sorry for my english is not good.
Sometimes other electric using equipments make electirical noise.(fans ,microwaves,some bulbs,elevators ).Fans with frekans invertor give electircal noise back to circuit and makes noise all sound systems.We are dealing with these systems on building automation systems.İn a 5* hotel after putting a frekans invertor to a fan ,all anfi's started to make noise even 100 mt aways.When we closed invertor all noise disappears.After we installed high capacity filter (electrical) all sound problems solved.
You must check all your electic using equipments maybe your neigbours.
I'm also planning my first real digital piano and thinking CA 65.Now using Yamaha DGX 640.But your sound problem third in ca 65/95 series in these forum and up to these time no solution appears.I started going away from CA 's.But where I don't know

I spent €14,800 for my N3. The pedal harp was not correctly installed ... and the movers made the same error I might have made. I spent a few minutes under the piano, realized what I had to do, and did it. I could have called the dealer who was about an hour away but I did the work myself and mailed my suggestion to the Yamaha tech in Germany for future reference.

KAWAI Man....seems there's always some of US who get stuck...trying to fix our keyboards. I have the new Kurzweil SP4-88, marvelous sounds...had trouble twice and had to mail it back and forth to Mississippi(Memphis area...), as of two months ago---attention is directed to the Middle C area---the D # or E flat has dropped out! ....yes, can you imagine...if I open full the Volumne control...you can hear a distant 'muted' thud, have never taken it out on a gig, afraid too! ....so, we all get stuck...just about two years old. Will have to try and contact Kurzweil at Woodlawn Hills, CA or donate to a 50lC-3 for taX purposes; hopefully we can get it repaired...the Kurzweil People are not 'existent' at Waltham, Massachusetts ??...at least- I thought I'd make you feel good, if nothing else. Mr. Kawai was hired away to Yamaha many years ago...I guess, he was as good as Ray Kurzweil....dSav(Maine)

The Kawai CA 95 is realy a beautiful piano. Impressive pianosamples, very nice keyboard, great speakersystem and a good looking cabinet. Just try it, and judge for your self. It would be a pitty if you miss such a beautiful piano just because some problem stories, mine included I'am sure the problem with the electric hum will be solved by Kawai. I have spoken to the dealer already and he will come by at my house to listen to the hum. Then he will send a Kawai technician. Ofcourse I hope when a transformer has to be replaced, that it can be done on the spot.

Have worked on many humming problems in electronics. But not piano's. Transformers can have noise issues. Transformers are epoxied to stop noise and can break loose from there bond. The other parts can cause this is a leaky Capacitor and/or a regulator. Which will loosen the bond on the transformer after time. Post back on what the tech finds. You can put a small peace of wood up against the transformer (there might be more than one) with little pressure and listen to a change. Your tech will do this if he has the experience w PCB repair.

Cool, have it fixed. That's easier and more convenient than a replacement . Good luck, j

Hi Dutch Dhamma - has this been fixed now?

I also notice a hum from my new CA65 and would like to know your outcome. If it is fixable, I might mention this to my dealer.

I believe you are correct that it is a transformer noise; it comes from the right hand side of the piano - which is where the power cord plugs in - and is only present when it is turned on, and is still there if you plug headphones in.

Cheers

Alan