Your Synthesizer Keybed: How It Works, and How to Fix Problems

Рет қаралды 9,197

Күн бұрын

In this video I describe the mechanical and electrical design behind the keybeds in our synths. I take one apart to show the inner workings, then demonstrate channel and polyphonic aftertouch, showing the mechanism inside the keybed that makes each of these function. Lastly, I talk about the various types of problems and failures we commonly see in our keybeds, how to identify them, what causes them, and how to fix them.
DeoxIT Fader F5 Cleaner: amzn.to/3hQkI7q
0:00 Intro
0:41 Mechanical Design
2:03 Disassembling the Keybed
2:31 Electrical Contacts
3:19 Velocity Sensitivity
5:02 Channel Aftertouch
6:18 Polyphonic Aftertouch
7:16 Aftertouch Mechanisms
8:30 Problems: Keys Not Playing
9:23 Problems: Inconsistent Keys
11:54 Summary
#Keybed #Keyboard #Synthesizer

Пікірлер: 76

@jjdekay6969 Жыл бұрын

EVERY synth player should at least watch this video twice! Very short, straight forward and to the point !!

@ScottsSynthStuff Жыл бұрын

Thank you for the kind words!!

@77news97 2 күн бұрын

The explanation about how velocity sensitive keys work was cool. I once had a key that worked intermittently. I took the synth apart, and under the rubbery thing, I found a dead pseudo scorpion (look it up) that had crawled in there and got squashed when I played the note. I cleaned it off and it worked fine. The way he was able to crawl in there, is that there are little openings, so that the rubber doesn't burp when you press the key!

@Protoxy Жыл бұрын

Excellent video thank you ! I've seen a project on internet where someone replaced his polysix keybed with velocity sensitive one. He then replaced the 8049uc key assigner with an arduino and changed the VCF amplitude out of the key velocity

@ScottsSynthStuff Жыл бұрын

Interesting idea. Now that I'm familiar with the voice board circuitry, I can see how that could be done. It wouldn't be simple, but definitely possible.

@schance1666 2 ай бұрын

Saved me yet again with your repair vids!! My Roland JD800 key contacts were so grubby that alcohol and erasers didn't fix it. Barely/gently scrubbed both the key contacts and the carbon dots with some steel wool, blew-out/vacuumed the dust, and the keys are playing evenly now. What a PAIN!!! But so nice when its done.

@MarkSomosoMusic Жыл бұрын

great job... amazing ideas on fixing the board.... i have repair video also

@jonathanredman8497 5 ай бұрын

Many thanks for posting. Just given my UF8 a proper overhaul using your info. Lots of helpful Tips here. Cheers.

@kurikokaleidoscope Жыл бұрын

Hapoy New Year ⚘

@Trancelistic 8 ай бұрын

Thanks for this video. I knew most stuff but this helpt out and was intresting.

@georgesbahia Жыл бұрын

Magnifique explication Super Vidéo. Merci beaucoup. Muito obrigado

@PhrygianPhrog 10 ай бұрын

Excellent

@TheSplitzMusic 2 ай бұрын

Id like to see the aftertouch repair process for roland d50

@Asmuk 3 ай бұрын

Hey Scott, thanks for the video, brilliant as ever. Would you consider taking more time explaining the difference of the pin configuration? For instance, the Opsix has a 15 pin connection, the Yamaha Mx has a bunch of cables, and so on.

@ScottsSynthStuff 3 ай бұрын

They are all unique, proprietary, and sometimes unique to individual synths. Some send a matrix, some send digital serial. Probably out of the scope of this channel.

@searchiemusic Жыл бұрын

thanks dude

@aggband5633 Жыл бұрын

Thanks for the video. I found a video on the polysix that actually recommended using a rear window defogger repair kit which had a conductive liquid that could replace the carbon if it was beyond cleaning. It sounds weird, but it fixed all of my korg keys! (I only had three working before haha) Definitely worth cleaning first, it for 10 bucks it's a great last resort instead of having to buy new ones. Best of luck with the polysix!

@ScottsSynthStuff Жыл бұрын

I've used that to fix window defoggers before...but for the membrane pads, I've always used Caikote, which is specifically designed to fix this type of problem: amzn.to/3QuYpRG

@ingolf7411 Жыл бұрын

Thank you very much for your valuable work on repair and servicing ... and not to forget ... a happy new year for you and your family.

@darienowns 3 ай бұрын

I sure didnt expect steven tylers brother to be on youtube

@waltscott5 2 ай бұрын

Very informative. I love that keybed and its variations, from the DX7 to the motif, from korg M1 through to the Triton. My big mysrery is that I’ve never understood velocity ‘gain’ vs ‘offset.’ They all seem to have the same to philips head adjustments but i’m afraid to experiment and mess it up. Have you run into that before?

@asdfjkl227 6 ай бұрын

Wow, just like "membrane" computer keyboards. Cheap, reliable, simple.

@jamesmoore2223 6 ай бұрын

what about occasional double triggering on my poly61? It is especially noticeable with little to no release

@nexuzeb79 Жыл бұрын

thanx Scott for clearing that out for us! More like this please, have you seen markusfuller?

@ScottsSynthStuff Жыл бұрын

Yes, I love his channel! Thanks, there will definitely be more...

@DRGAUTAM123 9 ай бұрын

Good. I got confidence as one of my key is taking hard press to sound. I'll open and clean it. I've another keyboard yamaha psr 520. It's display has got so fade that i can not read anything on it. It's display could not be obtained anywhere. What can I do? May I please get your help? Thank you.

@itsJoel59 Ай бұрын

Can I also use the Deoxit Fader F5 on the contacts on the board where the rubber contacts connect when pressed? I noticed in your JD-800 video that you used Deoxit D5 instead. Great videos!!!

@ababababeebababa 6 ай бұрын

Scott, great video as usual. I think I've watched this one twice. Do you have a recommendation and/or video on how to properly grease the keys? I recently fixed a couple yamaha psr keyboards and incorrectly (?) removed all the grease, and now they are quite noisy, but work fine. I was wondering "what would Scott use" ? As I know they sell some horribly expensive yamaha grease for like $30 for a tiny tube ... I was thinking is this just high quality silicone grease?

@ScottsSynthStuff 6 ай бұрын

I didn't want to buy the Yamaha grease either, for the same reason!! So I found the listing for the Yamaha grease, then looked up the MSDS to see what was in it - and it's just lithium grease. So I use standard white lithium grease, and it's worked great for me - doesn't dry out, and works perfectly.

@kimvin9 Ай бұрын

Thanks Scott. I took my Korg Kross 2 apart and cleaned the motherboard. I didn't change any of the rubber strips, because they were all in tact. I did notice that wiping the motherboard made a positive difference in the clarity of sound. I used Q-tips that I dipped in rubbing alcohol to clean the mother board. I had a lot of dust and specks of debris that fell or settled inbetween the keys over time. I still have that sporadic loss of sound as I'm playing. I talked to a repair guy at a local music about the sound drop. He mentioned a sound generator but he didn't really go into detail about it. To your knowledge, is the sound generator an easy removable part? Thanks. Best wishes

@ambidex Жыл бұрын

I love this video, and so many more I've found on your channel. You get in depth in a way the Tech in me loves. I was hoping this video answered a question I have. My 1st Synth was a Yamaha SY22. I hadn't played it for a long time and was able to play it recently and felt that the velocity sensitivity was very hard, as in playing hard or light made a difference, but not as much as I remember. What would cause that? The Sy22 has a Yamaha LC C61K6 keybed, like the SY35. Also, just in case soon, I'll need to replace 2 basic switches on it, the Yes/No +/- switches. They are the main buttons pressed, and I probably beat the hell out of them, creating sounds as a teen. Any idea how I can find out what switches I can use? They look like a very basic push button. But i wasn't sure. I also need to fix a key that no longer springs up (lowest key) but my guess is the little tab that holds the metal spring has snapped off so I may have to buy about replacement or rig a way to create a tab to hold that spring down. Anyway, great channel!

@ScottsSynthStuff Жыл бұрын

It's possible the keybed just needs a cleaning, like I show in this video. Until you open it up and see, you won't know for sure. As for the tactile switches, what I normally do is open it up and measure the switches that are there with a micrometer - the number, electrical layout and spacing of the terminals, the overall size of the switch, and most importantly, the height of the plunger from the circuit board. Then I go to Mouser or Digikey and start searching for something close that will work.

@ambidex Жыл бұрын

@Scott's Synth Stuff Will do. Thanks!

@JoeLinux2000 Жыл бұрын

Extremely informative. Is a Yamaha Avant Grand keyboard much different or are the rubber contacts just activated by a more complex action?

@vladtirla8801 7 ай бұрын

So if the aftertouch stops working, we need to replace that strip? Or I need just to clean it .Thank you for this video.

@learnmusicwithme4170 5 ай бұрын

What about cleaning the circuit board where the carbon connects? Clean with alcohol? I've seen other videos that say that alcohol has remove the carbon surface from the circuit board. Also, what if the entire keybed doesn't respond at all? Bad cable?

@erymanthonseth9295 Ай бұрын

Hi, thank you for this interesting video. I have an issue with my Roland D-10 which is similar but not identical to one you described, maybe you can help me. The issue is that the lowest 8 keys only play once and then become non responsive. The sound is at minimum velocity no matter how hard I play, and keeps sustaining until reboot or until I run out of polyphony playing other keys. Oftentimes, the problem will fix itself after a while that the synth is powered on (like one hour or so). I opened the thing up today and ran some continuity tests with my multimeter, I seem to have found nothing wrong with the wires or keyboard itself. I cleaned up the cable sockets with contact cleaner spray, but to no avail. Do you have any ideas about this at all? The only thing I can think of is that the gate array IC chip that does the key scanning has gone bananas, in which case I am screwed. But I would think such a failure would affect the entire keyboard? Any help will be greatly appreciated. P.s. a few years ago this synth had this problem, I played keyboard very little at the time so I didn't care. Then somehow it magically fixed itself and kept working for years until a couple of days ago. Weird...

@kimvin9 Ай бұрын

Thanks for the dtailed explanation you gave. I was wondering could it be a tone generator issue or a faulty capacity issue if the sound intermediately stops playing? The sound on my Korg Kross 2 88key workstation stops playing sporadically on different keys. The sound will come back after I tap on the keys. However, sometimes it comes back soon after tapping on the keys, but then sometimes it takes quite a few seconds longer for the sound to start back playing again. I was hoping maybe I could fix it. I'm going to get some more rubber contacts first to have them handy. Are you familiar with Korg sound generators and the capacitors possibly going bad which may cause unforeseen sporadic drops while playing? And thanks again for the detailed explanation of your video.

@DanielOrtiz-fm5lq Жыл бұрын

I just inspected a casio ct 770. One track was damaged,wich i repaired, but the lower half of the keyboard didnt recognize velocity

@wikashdebitewari 4 ай бұрын

Very interesting Scott! I have a question, maybe you can help with this: Do you know if it is possible to replace de Roland FA06 keybed with a better quality Fatar keybed?

@goodvibesprotest1220 7 ай бұрын

Very good video. Thanks! I have a problem with releasing some keys triggering te note (full vel). Mostly when pressing harder on the key. Even whit slow/soft velocity, but hard pressure. My rubber strips has 3 carbon pads. Any idea?

@nickmeredith002 2 ай бұрын

Super super interesting and informative video. I'm glad I found it! I have a problem with my korg though that isn't discussed in the video. I block of 6 keys seemed to sporadically stop working. That was discussed, but that problem seemed to resolve itself on its own. Now though, some of those same keys just play on their own. I'll be playing in a different area of the keyboard and then one of those notes will just play without being pressed and sustain indefinitely until I have no choice but to turn the whole thing off. What causes this and how do you fix it? Any help would be greatly appreciated.

@ScottsSynthStuff 2 ай бұрын

That's usually a single wire in the connector or wire between the keybed and the synth - it could be a broken wire or a bad connection.

@nickmeredith002 Ай бұрын

@@ScottsSynthStuff OK. I'll have a look at the wires and see if anything looks amiss.

@ozhantasdemir2815 5 ай бұрын

is there any way to fix velocity issue without opening the keybord

@OutBoardTink62 8 ай бұрын

I have a Yamaha P125 and one note is out by middle C an F drives me crazy .I have cleaned the contacts multiple times done visual for broken traces,checked diodes, no luck. Key has the plastic piece intact that touches the rubber.I do have a new middle range board but would like to get the original back working first if possible before changing the board.Any advice?????...thanks Glenn

@abeltrujillo8413 Жыл бұрын

Thank you for your video! I wonder if you would give me ideas on how to repair a continuous group of dead key on my Korg N264 I cleaned the rubber strips and carbon contacts but nothing changed. Any help will be much appreciated

@eclectico78 8 ай бұрын

Did you figure it out?

@pcuimac Жыл бұрын

I have two old Yamaha YS 200 and both have no good Aftertouch response. Do you know a company that makes Aftertouchstrips compatible with old Yamaha synths? thx in advance. Velocity is the first derivative of your location coordinate aka x(t)/dt = v(t). v(t) is proportional to the acceleration a(t_0) necessary to achieve that velocity after a time intervall t-t_0. Since pressure P is proportional to the Force working on an area and a Force is a(t)*m, velocity is a good measure for the pressure needed to accelerate the key of a given mass, esp. if the mass is the same for all keys on a keybed.

@ScottsSynthStuff Жыл бұрын

It all comes down to energy vs time. :) I would give the people at Syntaur a call - they have them, and might know what resistance value you would need.

@yamahamotifxs Жыл бұрын

Since you also have a Roland Fantom 6, I think you have also experienced that the keys of the Fantom 6 are of excellent quality, but quite noisy due to the keybed. Is it possible that Roland saved a lot with the felt or rubber under the key? I don't know what's under the key, I didn't take it apart, because it's still under warranty, but many people claim that there is not enough felt under the keys, and because of this, the keybed rattles a lot when I hit the key harder. I think that's why Aftertouch is also bad on the Fantom synthesizer. You have to press the keys quite hard to get it to respond, especially with the black keys. What do you think is the problem with the keyboard? I love the Fantom synth, but its keyboard is very noisy.

@ScottsSynthStuff Жыл бұрын

I have heard from people who replaced the felt in their Fantom with a thicker one, which reduced the noise of the keybed, but it did not change the amount of force required for the aftertouch. On the JD-800 I was able to change the aftertouch force electronically by adding a resistor, I suspect you might be able to do the same on the Fantom, but I'm certainly not going to try it. For whatever reason, the channel aftertouch on most synths is extremely stiff and hard to use. I don't understand why they do this.

@abeltrujillo8413 Жыл бұрын

I should have waited to watch the rest of the video 😅

@sugnasugna 9 ай бұрын

Hey Scott, I'm working on a keybed similar to the one shown in the video, it's from a poly800, where the lowest 31 keys are unresponsive. Ive probed around with my multimeter for an hour and found continuity between everything. I'm worried it might be an issue with the A/D converter chip or the bussed resistor, any clues? I'm not sure what to do next or how to diagnose the issue.

@joshuaswannmusic6462 Жыл бұрын

Can this be done with a MODX?

@bcm70 Жыл бұрын

Great video. Question for you - do different manufacturers use different communication protocols to transfer signals from their keybeds to the synth engine attached to them? I stumbled across your video doing research on how keybeds work, as I'm wondering how hard it would be to pull apart my Opsix, buy something like an old Mk1 S61 Komplete Kontrol midi controller to steal its keybed, and then put the Opsix synth and front panel and the KK keybed into a custom made enclosure to create an Opsix with a decent sized and nicer keybed. However if every manufacturer uses their own comms protocol I might be out of luck.

@ScottsSynthStuff Жыл бұрын

Internally it's typically not a communications protocol at all. That would require the keybed have its own processor, to read the state of the keys and then transmit it to the main processor. Internally, virtually every synth uses a scanning system for the keybed. The keys are arranged electrically into a grid. The synth has scanning circuitry (or just uses the main CPU) to energize one row of the grid, then checks the columns to see which keys in that row are pressed down. Then it energizes the next row, and scans the columns again, until it's read all of the rows, then it starts again. This happens extremely quickly, hundreds of times a second. This allows the quick scanning of the keybed, without having to have a wire going to each key. Unfortunately, the key/grid layout and actual scanning requirements will vary in different synths and manufacturers, so there isn't a "universal" keybed that you can just stick into it and expect it to work. The Opsix will have scanning circuitry that has the capability to read only 37 keys, because that is what it is designed for. You aren't going to be able to stick a 61 key keybed in there, because the circuitry and firmware to read 61 keys doesn't exist. Some people have gotten around this by transplanting a MIDI controller into a case, then internally (or sometimes externally) routing that keybed into the synth's MIDI IN port. I've seen this done on several JD-800's to replace one of the famous "red glue" failed keybeds.

@bcm70 Жыл бұрын

@@ScottsSynthStuff Thanks for the reply. I did a bit of digging after I posted my question and ran across the scanning technique you've described so that makes sense. Getting around the hardware issue using MIDI seems like a bit of a kludge. Guess I'll just have to hope that they release an Opsix SE one day. Not holding my breath given it has been two years since they demoed the Wavestate SE and haven't actually released it.

@StabilAmboss Жыл бұрын

Is there a resource out there on what keybed is being used in midi controllers/synthesizers/digital pianos? Is there information on the which keybeds are better than others i.e., last longer, more reliable, prone to issues etc etc ? Also is there any relation between the keybeds and actual weights (semi weighted actions, full weighted actions) of the keys? Thank you.

@ScottsSynthStuff Жыл бұрын

How funny that you should ask this, as I have a video on keybeds coming out on Sunday! I answer some of those questions for you in it!

@StabilAmboss Жыл бұрын

@@ScottsSynthStuff Wow, lucky timing! Looking forward to it.

@sunnyboner676 6 ай бұрын

I’ve been wanting to purchase a Yamaha YC61 but heard that the keybed has issues and concerns about its longevity. Does anyone have experience to share?

@zinzermunch 3 ай бұрын

I have a Korg Krome 88 weighted keys, one of the keys is a bit slower coming back up after being pressed, is that a common thing on new keyboards or should I return it? It makes it difficult for fast runs on that key.

@khawk2012 Жыл бұрын

Hello there. Great video. I still have a curiosity question.. My Roland Fantom is very hard to press in order to get the aftertouch going. Not sure if it's only mine but it also make more noise when playing the keys than my Montage. I tried adjusting it in the settings but still nothing.. is the aftertouch strip a preassure sensitive or is it just a switch strip and can it be adjusted somehow?

@ScottsSynthStuff Жыл бұрын

I have both a Fantom and a Montage, and I agree, the aftertouch on the Fantom is VERY stiff, I have to press quite hard to activate it - and it seems like when you do press into the aftertouch, it's all or nothing. It's very hard to modulate. The Montage is better, the Hydrasynth is by far the best, with easily modulated aftertouch. For channel aftertouch like in the Fantom and Montage, it is just a long resistive ribbon, like I show in this video. The harder you press, the less electrical resistance, and the synth measures that. There are adjustments in the Fantom, as you have said, but I found (as you did) that they don't have much effect. I think it's just the nature of the beast in the Fantom. I will say that in the JD-800, which uses the same system (that's actually what you saw me showing in this video), I was able to solder in a resistor that adjusted the sensitivity of the aftertouch to make it much more usable. You could probably do the same to the Fantom, if you really wanted to. I suppose you could solder in a potentiometer that would allow you to adjust it as well.

@khawk2012 Жыл бұрын

@@ScottsSynthStuff I thought about that but I need to look at another first. For what it cost I really don't want to touch it for now but it does seem like it needs Something to soften the keys. They sound like am banging on it.. my Korg X2 still has a better feel. Thanks. Am learning more as I keep reading 📚 and maybe I'll decide to take it apart and modify it one of these days.. that's the only reason why I sold the FA to buy this one.. 😎

@compassionatekiller7606 Жыл бұрын

Hey Scott! Thank you for the great video. I have a Yamaha PSR 260 keyboard that has the same issue with the keys 08:35 . I clean them and it works fine for a few months & then goes bad again. Any idea with might be the problem?

@eclectico78 8 ай бұрын

Did you figure it out?

@compassionatekiller7606 8 ай бұрын

@@eclectico78 Naah! Now my whole synth got bad.

@andrewleo1189 5 ай бұрын

Hey Scott I have a Roland Juno DS-88 I bought it off Facebook to learn piano got it for a good deal it was working fine and then a couple months down the road 2 keys don’t work white and black I took it apart I cleaned the carbon I switch out the rubber carbon from a different section of the keyboard to test if it was the contacts that didn’t work no sound on G3 A3 I don’t no what to do my uncle is becoming a pastor and I wanted him to use it for church I’m from nj and I’m trying to find a person that fix’s keyboards not so easy if you have any suggestions or advice that would be great thank you

@ScottsSynthStuff 5 ай бұрын

You've done the first thing I would have tried, next would be to look at the cabling - if you're not comfortable with electronics, it's time to get it to a tech.

@silverlicious2086 Жыл бұрын

Hi Scott. I pulled my vintage Mini Moog out of storage. I have not played it in about 5 years. It basically is in mint condition. Never been on the road. Anyways, I turned it on and many of the keys are acting as though I have the glide switch on. When I press a key, the sound wobbles up and then back down erratically. Then back up and down with no pattern ,rhyme or reason. With a mind of its own. I turned the glide switch on and off and still the same. I'm wondering if the contacts have got dusty or something. I'm hesitant to take the keyboard apart and may just take it in to a local vintage keyboard service company to have them diagnose. Your initial thoughts on the problem?

@daveogarf Жыл бұрын

Tes, check/clean the key contacts. If that doesn't help, check the sample-hold circuits for out of tolerance capacitors.

@ScottsSynthStuff Жыл бұрын

#1 thing is to look at cleaning the key contacts. Oxidation can do exactly what you're experiencing.

@silverlicious2086 Жыл бұрын

Thanks for the reply. I will look into this.

@silverlicious2086 Жыл бұрын

@@daveogarf Thanks for the information