box full of worn out keys

Six reasons why you should NOT buy a cheap brand digital piano

Lesedauer: 

ungefähr 10:05 Minuten

This is a write up from my work shop point of view, to help you make decisions when you consider buying a digital piano, whether new or second hand. I have serviced pianos from all kinds of brands, expensive ones, cheap ones.

Maybe you found this page because you were looking for a test or review. This blog post is not about testing pianos of brands like Altana, Classic Cantabile, Clifton, Cronenwerth, Fame, Gear4Music, Hemingway, Mc Crypt, Medeli, Schubert, Stagg, Steinmayer or Thomann. Instead, I will provide general information about pianos by cheap brands based on personal service experience.

Generally speaking the cheaper ones need maintenance earlier, sometimes after just a few months of playing and often because mechanical parts fail. More expensive pianos enter my work shop entirely because intense usage throughout many years makes e.g. the filt dented or electrolytic capacitors need to be replaced due to life cycle ending after some 20 - 30 years or so. Still, they are easily repairable while cheaper pianos will not even last that long for many reasons. Here is why.

1. Failing keys

This happens either due to dust or dirt on contacts because the contacts aren't encapsuled properly, or too little conductive material is applied to them. I've even had a case where corrosion in a cheap connector plug broke the piano after just 3 years. But since dust is enemy No. 1, as a conclusion, lay something on your keyboard while you are not using the piano. Hopefully you have a cover installed (and make use of it).

thomann dp-31 bad keybed engineering

Or there is a mechanical problem. I've had torn off and broken hammer rubber and plastic, worn out keys, bent axes. I've even had a Cronenwerth Piano with every single hammer broken just because someone played on it for a couple of years. Sadly, the original importers usually refuse to keep spare parts for more than two or three years so you either have to improvise or you have (or add to) a collection of spare parts from trashed pianos. While the European Union has started to force manufacturers to provide spare parts for a certain period of time from 2021, manufacturers of digital pianos are not (yet) among them.

classic cantabile dp-40 broken keys

There are brands that have products with really good keybeds, though. Classic Cantabile for example sometimes use keybeds by renowned italian manufacturer Fatar. Usually this is mentioned by adding to the type name of the piano, so in this case at least you'd get away with something sustainable.

Hemingway DP-500: worn out hammer rubber

2. Failing capacitors

It's electrolytic capacitors that are failing mostly. While good pianos are built on quality capacitors with good headroom (e.g. tolerating significantly higher temperatures and voltage than expected) the cheaper ones are made of parts that just meet the absolute electrical must, well, if this is ever met at all due to large manufacturing tolerances (~20%) and unselected parts. Since a cap life cycle is measured in hours (e.g. 2000 h) they can loose capacitance early and start to fail even if you just left the instrument switched on over night repeatedly. Loosing capacitance sometimes means leakage which leads to more issues. Symptoms could range from low volume on a stereo channel, crackling static noise or low voltage in critical parts of the circuit resulting in complete failure. In the worst case dying capacitors lead to shorts.

I've made the experience that SMD* caps fail more often than through-hole-components although they could be the better choice if selected properly. I have even seen exploded SMD caps due to lack of determined breaking point. You guessed it, SMD components are often cheaper than through hole equivalents. And if the manufacturer decided to use multilayer PCBs (Printed Circuit Board) SMD components are often a must for practical reasons.

exploded smd capacitor on pcb

I observed that in newer products even cheap brands tend to return to through hole components at least for some parts of the circuit which makes maintenance a lot easier. It would be better if they made this a general rule in my opinion, though.

One more word about a problem familiar even to high class manufacturers: (Before) some of them like GEM (†), Roland, Technics (†) and even Yamaha use(d) rechargeable batteries to buffer memory when the piano is switched off. These batteries tend to leak after many many years of usage, damage can be dramatic so it's a good idea to keep an eye on that if you own such a piano or plan to buy a used one. If you have a memory function and there is no standard battery installed (e.g. CR 2032) then it's likely that you have something rechargeable instead. Watch out and have that component replaced after 10-15 years latest.

* SMD = surface mounted device, a technique to make industrial manufacturing easier and improve electrical quality because components can be made much smaller

3. Failing pots, faders and switches

This applies generally to all manufacturers of electronic devices. But you can use cheaper or better components for your products. While better pots often can be revived by cleaning them, cheaper ones have their conductive material lost and are only to be replaced. What's more, sometimes it's not easy or even hopeless to get spare parts with the same specification and dimensions.

4. Poor manufacturing quality

In (junk) industrial manufacturing all parts are preconfigured, like predrilled housing screw holes or automated placement not only of circuit board parts. Despite the fact that robots do a lot of the manufacturing work, controlling is essential. Whenever I came across a cheap brand piano I spotted indications of inattentive controlling. Missing or misplaced screws. Badly placed or even wrong parts on circuit boards (while the boards itself fulfilled function testing somehow). Displays and LEDs not fitting their panel spaces (low quality displays by the way that become pale just after a few years). And hot glue on spots where it does not make much sense like on connectors that are self securing or wires that have dedicated supports anyway, always glue, glue, glue. My image of a junk industry controller is of a person holding a signing pen in one hand and a glue gun in the other.

Classic Cantabile DP-400: misplaced ic in cheap china digital piano

Still, it's kind of sympathetic that the IC's in the above image are marked LOL.

5. Built not service friendly

Especially chinese manufacturer(s? Plural? See below!) seem to save costs whenever possible (presumably pressed by western online- or chain stores). Sadly, this policy applies also to certain connectors between circuit boards, most of all panel boards. So if some replaceable component failed you have to disassemble all of the boards because all wires are soldered AND GLUED (!) onto the boards. Why do engineers do that? Don't buy that. Nobody wants to repair it.

glued wire connections

6. Poor sound quality

These cheap ones sometimes have tons of sounds and functions onboard. But they don't sound good at all. Speaker types and filters are not well trimmed to the housing which often results in a certain frequency range (often low mid) being too dominant. And they tend to have strange dynamics. They are noisy. Even their transformers hum. D/A conversion often sounds like there was no improvement since 1983. Take a pair of headphones and listen to a single note while it sustains, how long does it sustain? When is it getting noisy? They're trying to paste up noise with reverb, right? Reverb can't be switched off permanently, right? You got it.

My rule of thumb:
If the total price per button ratio is below 20 € (or dollars), don't buy it. This means a 400 € piano should not have more than 20 buttons/controls.

What kind of digital piano should I buy?

If you don't have much money, rather buy a 20 year old Yamaha, Roland, Technics, Kawai, Korg or a later Casio, than one of these cheap brands that are supposedly manufactured all in the same factory run by Mede‍‍li in Zhuhai/China. If there are issues with second hand pianos from the above name brands they are often easily fixed, as long as it's not a leaking-cap-problem (see above). And often you still get spare parts for them even after many, many years. I have revived digital pianos from the 1980s and early 1990s that still sound better than nowadays 500 - 600 Euro China products.

If you really need to buy a chinese piano, never buy it second hand. Prefer buying it in a physical shop and ask for guarantee, service and sustainability. If you really need to buy it online, I don't recommend buying on a site that is not properly translated or missing imprint and contact address, or on Amazon or Ebay. Someone will have to service the instrument sooner or later, and it's not unlikely the money you saved when buying will be spent on service (and transport). If service is possible at all.

Exceptions to the rule?

Yes, there are a few pianos from the better brands that keep having issues. Short list from my experience:

KORG SP-170 (key contacts fail too quick, too little conductive material on rubber contacts)
YAMAHA P80 (keys break after a long time due to wrong fat, an issue common with some other models from the early 2000s)

Questions? Additions? Comments? Insults? Feel free to leave a message below.

 

Comments/ Kommentare

#01

Hi,
What do you think of the medeli digital pianos like the DP-330?

Thank you

Hi Mehdi,
I don't know the DP-330. But let me tell you that I fixed most pianos that entered my work shop, except for 4. One by GEM (a company that built excellent pianos but vanished a couple of years ago, so no spares) and three by China brands from the Medeli factory, all of them due to low mainboard quality and a very time limited spare parts policy. The pianos may last if you use them carefully. But if you read the article you know what I would recommend. Choose wisely!

#02

Hi Henrich,
Thank you for the article, very useful.

What do you think about Classic Cantabile DP 50 WM? I am planning to buy one for my mom which is 60 y.o. and planning just to start to study to play piano, is it worth? I like how it looks like and the price is okay but couldn’t find a lot of info on internet about the brand and the model.

Thank you!

Hi Nicu,
if you read the article carefully you will find the answer... I've had a DP-50 in my workshop once, with a non repairable mainboard issue. Was it possible to get a replacement for this? Nope.
Choose wisely. Don't choose by price but by long term support.
Cheers
Ulf

#03

Hello!I am thinking off buying a digital piano-my son studied music.I looked all the brands and all the caracteristics-i want some thing that woud be the most closed touch to the piano keys!I don t want to pay a fortune,but i don t want also to choose badly!I looked Roland,Yamaha,Thomann,Cantabile...
I must tell you that it is difficult to decide and choose!Can you help me?

i have a real :) piano in my house,but it is heavy and difficult to transport,so i wanted to offer him a piano with good sound and endurance ,where he can play Chopin or Muse!

I hope that you can bring me some ligth and help!Thank you for your help!

Hi Maria, you'll find the answer on this page. Stick to japanese and korean brands. Good luck!

#04

Nice comments. And I agree.

I have a GEM Promega 3. Luckily the electronics are still good and, also luckily, it has Fatar key action for which there actually are spare parts available (although it's a TP30, but the rubber from TP40 seems to be the same).

What I don't like about it, is the serviceability as you pointed out. Although it's not as bad as what you described, I still have to disassemble almost the entire keyboard in order to replace the rubber contacts. And if it fails, I'll have to do it all over again.

What do you think about the VPC-1? Do you have experience repairing it? Can you talk about that a bit? It looks as if contacts can be serviced quite easily because they are place at the back and above the action. Can you confirm that?

There are posts regarding the VPC-1 on pianoworld forums that don't look good at all: the key response velocities seem to be all over the place and with no easy way to calibrate. Kawai also has the NV line, ie the NV-5 with optical sensors. Do you think the optical sensors make sense or are the rubber contacts underrated and only badly calibrated in the VPC-1?

Generally, do you know about method to calibrate key response velocities?

Hi Marc,

thanks for your comment. I can't give you advice regarding the VPC-1 or Kawai NV. I do piano repairs entirely for my social project "Keyboards for kids" so I usually get quite old instruments, except for chinese ones because they don't age well. Regarding sensors, anything that might collect dust is bad, anything encapsuled well is good.

Regarding the Fatar keybed, yes it's annoying, but chances are good to revive a keybed once properly cleaned. There are usually two contacts to calculate the velocity, which is lost once only one of them is dirty. Use isopropylalcohol or benzine that evaporates traceless to clean the rubber contacts. This works usually very well. And keep an eye on the internal memory backup battery, since I know of leaking batteries in other GEM pianos leading to complete failure. If it's not a standard CR2032 battery (don't know the Promega) it's likely to be a rechargeable one that you should replace after some 10-15 years latest.

Good luck/

Ulf

#05

Hi,
Do you have any experience with the DYNATONE brand?
I just have the opportunity to buy a Dynatone DPS-8H digital piano (5 years old for 500€).
All I know is it's made in Korea.
What do you think about that, please?
Thanks for your answer.
Jaro

Hi,
no.
Cheers,
Ulf

#06

Hi Ulf, great page!
I own a Roland HP900 that works fine after all these years and I can buy loads of spares.
My dad on the other hand owns a Fame DP100 (2010, from musicstore.de). This stopped producing any sound, but all the buttons still seem to work along with the little screen. The mainboard still looks good, but I'm trying to get hold of a replacement to test if that is the issue.
Do you have any idea how to gt hold of such a thing?
Thanks

Hi Bas, thanks. If Musicstore in Cologne can not provide spares nobody can unless you tatter another working DP100 with e.g. broken keyboard. Check
- if the piano supports MIDI Local and if that is set to OFF accidentally
- does the headphones sound, is there a headphone adapter stuck in the jack
- if you can route external signals into the piano, do these make sound
- did sound off happen suddenly or was there some progress over a certain amount of time
- if you are familiar, check voltages from the PSU board/part, typical voltages could be +3,3V, +5V, +/-12V, sometimes even +/-15V

If the problem developed over time, electrolytic capacitors might be the problem. Any radio/tv service technician can solve this. Good luck!

Hi Ulf,

Thanks for the comments!
Sound off was a sudden event. The caps look ok, but good to know there won't be any help from the Music Store. I'll try your Midi and the external sound suggestoins.

If that doesn't help, we'll give it to a charity shop and purchase a big-brand piano for my dad.

Thanks for your time!

Bas

#07

Hi. Have you ever dealt with a gear4music DP60 digital piano and are you able to get schematics anywhere for these? Or is there anyway to get service manuals for this Asian made instruments?
Thank you.

Hi Steven, no, no, and don't know. If you are lucky to get schematics of any of these chinese, chances are the boards are quite alike. Good luck!
Ulf

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