Korg Forums

[easily_confused]

The dial on my SX skips. Anyone know how to fix this issue?

I have a bunch of dumb questions.
Is this a rotary encoder (I expect it is)? Is it optical or contacts? Does contact cleaner help? Are there connectors (like ribbon cables) that get dirty? Does it make sense to open it up and reseat everything?

[hazabikit]

Hi there,

It sounds like you might be experiencing the famous "knob jitter" issue.

See this thread for a solution: http://www.korgforums.com/forum/phpBB2/viewtopic.php?t=70030
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"It was really like jewelry work, working precisely." -- Guy-Manuel de Homem-Christo

[Wavemaker]

I 've got a skipping dial on my esx too. The esx is the old smart media card model from 2003, but i don't think it matters i think both old and new electribes have exactly the same dial wheel.

hazabikit, i don't think it's the same problem with the one described in the link from DrNibbert. I don't have any of these problems on my emx and esx that DrNibber describes, it's just the dial skipping at a specific point and instead of going forwrad it goes backwards.

Same problem goes for other Korg gear such Tritons and pa series, the dial skipps after too much use and needs replacing.
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Gear: Korg pa700, Roland Fantom X6

[jefe]

I've got a smart media ESX-1, I'm learning on it, it's barely used, really. The dial started skipping last week. It makes me nervous.

But, yeah, that's the only issue with my machine, nothing like is described in that thread on the EMX.
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Korg gear:
D3200, D1600mkII, Electribe ESX-1, MicroKorg, KP3

[thehighesttree]

It's called an endless rotary encoder and it seems to use physical contacts (the clicky feeling inside). Not sure how many positions. You could try contact solution to see if that works (ask for DeOxit knob and slider spray from your local music store) but I don't know that it will. As far as I know this seems to be a common concern with the X Electribes but I haven't encountered it yet.

I'm pretty sure there's a service manual floating around somewhere online but I can't check right now. You could find the exact details on the part if you find this and look in the part listing.

[X-Trade]

It's a common problem with many alpha wheels. Completely unrelated to 'knob jitter' which is an analog potentiometer issue.

I had an ales is drum kit which couldn't go faster than one step a second without going backwards, from day one. Fortunately don't have this problem with my ESX or any keyboards yet.
Radias used to do it but mysteriously stopped a couple of months ago

so I think cleaning out with compressed air may help - probably won't do any harm either even if it doesn't help.

The switch is basically just a forwards/backwards contact which is clocked over by teeth like a gear on the wheel.
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Current Gear: Kronos 61, RADIAS-R, Volca Bass, ESX-1, microKorg, MS2000B, R3, Kaossilator Pro +, MiniKP, AX3000B, nanoKontrol, nanoPad MK II,
Other Mfgrs: Moog Sub37, Roland Boutique JX03, Novation MiniNova, Akai APC40, MOTU MIDI TimePiece 2, ART Pro VLA, Focusrite Saffire Pro 40.
Past Gear: Korg Karma, TR61, Poly800, EA-1, ER-1, ES-1, Kawai K1, Novation ReMote37SL, Boss GT-6B
Software: NI Komplete 10 Ultimate, Arturia V Collection, Ableton Live 9. Apple OSX El Capitan on 15" MacBook Pro

[easily_confused]

Thanks for all the comments.

Rotary encoders are quadrature switches. They are two switches that open and close as the rotor is turned, but not at the same time so they create ovelapping pulses with a 90 degree phase relationship. By looking at the pulses you can tell in which direction the knob is being turned and how much it was turned.

If the contacts get dirty the data will be screwed up. Also If the design is poor and there is not enough current being switched the contacts will oxidize (most common design problem), or if there is too much the contacts will collect carbon go bad.

I sprayed contact cleaner from the top and it seemed to get better, but it has not been used much since. I'll post again once I know for sure.

[los vlados]

I have the same problem with my EMX /the old model/ and I tried with contact cleaner and same other sprays but the problem is still there. My question is where can I buy a replacement encoder? I have tried to contact the http://www.guitar-parts.com/ 2 months ago and when I spoke with them and first everything seemed to be OK, they stopped to answer my mails and they've never sold me the encoder. Now they are no more available there. Is there some other place where I can purchase that encoder. The encoder is this -
http://www.guitar-parts.com/catalog/korg-rotary-encoder-pot-d1600mkii-and-others
P.S The strange thing is that everytime, after leave the EMX to work for an hour, the encoder work better and is not skipping so much but is still skipping.

[easily_confused]

The Problem is Fixable:

The problem is caused by silicon lubricant inside the encoder that drifts onto the contact area. The encoder can be disassembled and cleaned, but you need to be real careful not to mess up/bend the spring contacts. No soldering is required.

This worked for me, but I can make no guarantees it will work for you.

To disassemble the unit:
1. After removing all the knobs, remove all top torx screws are remove the big metal plate
2. Remove the 4 silver screws around the tube window. Don't remove any of the black screws through the top thin metal sheet.
3. Lift out the whole assembly and fold it to the left.
4. Disconnect the ribbon cable in the lower right corner of the assembly you just lifted out. To disconnect, pull the white plastic housing towards you. There are little lips on the sides. This will release the 3 wire ribbon cable. When you reassemble, you have to slip the cable in until it seats and then push the housing closed. Be sure to push the cable in far enough (check it by pulling it lightly after you close the housing)
5. Remove all of the black screws that go through the circuit board.
6. Now lift the circuit board and fold it to the right. Be sure the rubber switches stay on the left. DO NOT TOUCH THE CONTACT AREAS ON THE CIRCUIT BOARD OR THE CARBON BUTTONS! ESPECIALLY AFTER YOU START MESSING WITH THE THE SILICON.

You can now see the left encoder. It is a gray metal housing with 4 metal clamps holding it together. Carefully bend the clamps back just enough to to lift off the top part of the encoder.

You now have a two piece assembly in your hands. The contact rotor and the metal housing. If you look at the rotor contact face you will likely see lots of silicon goop. Wipe it all off and clean its contacts. I also wiped off most of the silicon in the housing so it wouldn't drift back. I left a little in the housing.

On the board there is the fragile contact assembly. There are three little springy contacts and the detent device. I don't know how to tell you to clean the contacts. I tried with kleenex and a toothpick and nearly destroyed the unit.

Try to get any silicon off the contacts.

Put the rotor back into the upper housing and place them back onto the lower assembly. Bend the clamps back into place, and you are done.

I partially re-assembled and verified it worked, then put it all back together.

Again, I can't be sure that you have the same problem that I did, but it worked for me.

[cooptrol]