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Encoder accuracy (bourns) MB-6582?


Arkay

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I still haven't sorted this. Very luckily for me though I live about 10 mins from Wilba's place and he kindly offered to take a look at it for me.

I already ordered 14 replacement encoders (the same as Hawkeye mentions above), to put them in my MB6582. Wilba has these too and I imagine when it comes time to troubleshoot my machine that he'll end up having to remove and replace each encoder with these new ones. But until he's looked at it it's all conjecture. There might be some other issues. I don't know.

When he has had time I'll be sure to post the solution onto the thread as I know what it's like to finally find a thread that completely explains your issue but never says what the resolution was.

Stay tuned.

Cheers,

Arkay

P.S. For Hawkeye: I was following your guide when I assembled the CS (great guide!), and I remember testing each of my encoders to make sure they worked. Both with a multimeter, after removing the detents, and then in the machine, after installation. They did of course function in that I can move any value from fully off, through it's range to fully on, whatever it is (it appears to work as designed on every encoder). The problem here is only on fine movement when trying to set specific values. I thought everything checked out and moved on because I was testing for function, not control, having no real idea of what the synth is like to use at that time. I ended up soldering them in, and glueing them down, BEFORE I realised I had this problem.

Both those actions make this problem challenging to fix now. Can I maybe suggest a line item in your build guide to suggest that fine control of each encoder (setting specific values), should be checked before soldering the side tabs (the large ones) in place, and before glueing the encoders shut. As Wilba has since suggested he never solders the large tabs, only the 3 active pins on the encoders (which is already strong enough to keep them in place), as it makes them difficult to remove later should you need to.

Just a suggestion but it could save some people some grief ;)

Edited by Arkay
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As Wilba has since suggested he never solders the large tabs, only the 3 active pins on the encoders, as it makes them difficult to remove later should you need to.

All respect to Wilba, but I don't agree with this statement - not soldering the large tabs allows the encoders to wiggle around on the PCB when turned (unless they are fixed to the frontpanel). This is not good for the active pins and their solder joints. The tabs are there for a reason.

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Yeah. I know what you're saying. I may have misunderstood and/or quoted Wilba out of context. I think he was referring to the single encoder on the Sammich when he said that and it could have meant not soldering the larger tabs in place until proven that the encoders work correctly. So don't take what I said above as gospel.

Perhaps in Hawkeyes guide he could suggest only soldering the 3 pins in place at first until they are all proven to work correctly when the larger tabs can then be soldered and the glue applied to lock the encoders up... If any encoders are proven to malfunction you could then either pull them apart (while on the board), and try to bend the contacts into a better position before glueing), or cut the three pins to desolder and replace the encoder before soldering the larger tabs. It sounds like common sense to me now but inexperience is what guides are there to aid I guess.

Given the number of people that haven't had this issue it's clearly not common anyway. But all guides can always use more information from problem installs... :)

Cheers,

Arkay.

Edited by Arkay
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Good ideas! I have added a subsection to the guide, where it is recommended

a) to solder the three connection pins of each encoder first and check with the baseboard, that the encoders work fine.

b) afterwards solder the big tabs - stability matters in my opinion, too. Fully agreed with ilmenator.

Arkay, when you´re at Wilba´s place - say him a big hello from me and ask him, if he has managed to get the OLED up and running yet, i´d be interested ;-)

Many greets to downunder!

Peter

Edited by Hawkeye
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  • 3 weeks later...

Hey guys.

Finally got this resolved so thought I'd better post the results for anyone else that goes through this.

Was speaking to Wilba last week (he's been flat out), and didn't have time to look at my 6582 as yet, but he did loan me his SMD desoldering tool so I could have a go at desoldering the encoders myself.

Hawkeye (sorry man), forgot to ask Wilba about the OLEDs but I have to drop the tool back so will try to remember then.

Anyhow. Took the machine home and ended up not using the desoldering tool anyway. I desoldered a couple of encoders the old fashioned way, solder sucker, braid, and replaced some of the bourns encoders with the new ALPs ones.

The difference was like night and day. I left all the new ones detented too. But on the old bourns I could barely see a difference between different firmware setups (encoder3 vs encoder4) etc. With these, and the detents in place, it was very simple to detect the correct firmware setting to select the right encoder type.

I then proceeded to do the rest of the encoders. Some proved a little hard to get off but I had a technique and stuck with it and got there in the end.

Sadly though in my exuberance after I'd re-soldered all 15 new encoders I had 6 not working and 1 led that had taken a hit. Turns out I had put a little too much pressure under the encoders to get some of them out and must have broken some tracks on the board.

So it took me a little while to trace the circuit. I never found the actual breaks, but I did manage to solder 3 bypasses to fix all 6 encoders and the led.

So at the end I had a fully finished control surface that works perfectly. I was wrapped!!

Also managed to get the feedback pots installed. On the first 3 sids at least. I busted the 4th going for that extra half turn to line them all up! Grrr. Then I figured I'd never need feedback on all 4 anyway. Pots are an awesome mod though now I want some extra SSM2044s or something else too!

I also noticed 1 small problem in that if I switch the filter to ext on sid 4L I lose output. I haven't tracked that one down yet, and aren't that worried as it works fine for everything else and that engine doesn't have the feedback pot anyway now. So I'll use it for a "Standard Instrument" channel and it makes no difference.

I'm trying not to be anal and go for that "perfect, no problem build", that always results in causing more and bigger issues. So all things are sweet as they are.

In the end this entire thread was the result of some bitch crap encoders, purchased from Mouser. Either I damaged them during removing the detents which is unlikely as I was very careful, or they were just crap to begin with. I favour the later.

Moral of the story. There isn't really one. Bourns are used everywhere. I was just plain unlucky I think. One thing I did learn though is that there is no wierd stuff happening, no shorts or power oddities etc. It's very easy to convince yourself of inexplicable wierdness when in reality with electronics there's only so few things it really can be. I should've tried replacing an encoder much sooner.

I'm in the middle of assembling my MBSEQv4 now, it also uses bourns encoders, but I expect they will be fine. I've decided though that I prefer them with detents anyway and if you don't pull them apart then if they really are rubbish you can send them back for replacement.

Herein endeth the saga of the dodgy detent removed bourns encoders.

Cheers,

Arkay.

Edited by Arkay
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Hi Arkay, glad to see that you solved the problem!

I can actually see a pattern here with the Bourns encoders - they were used in E-MU samplers, e.g. the E-IV/64/6400 and Ultra series, and these have a reputation for the datawheel to break down rather soonish. It seems like those encoders were just not up to the task. Interesting to see that your built confirms this.

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Hi Arkay, Hawkeye,

A lack of a few other components at Mouser saved me from buying lots of the Bourns encoders with switch, sans detents. There's 200 on order that will arrive later next year so any of us LED ring board owners will likely need more, lots more. The Alphas used by the 6582 are twice the price sans switch - I have to locate a good alternative with switches that doesn't break the bank getlost.png

Best,

Johan

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I'm having exactly the same issue with my sammichSID I bought from somebody in Australia already built.

If I turn the encoder REALLY carefully, it proceeds 1 at a time to either direction, but the faster I move it, the more it just jumps randomly to diferent directions, sometimes in increments of several dozens or even hundreds.

So any idea for a replacement encoder for a sammichSID? And what about the firmware? Now I have the latest (just downloaded it a few days ago) sammichSID firmware uploaded.

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Taika-Kim - are you also using the Bourns encoders? If you tried all available different encoder types in the firmware and the problems still persist, you could try the alphas, they work very nicely for the MB6582.

http://de.mouser.com/ProductDetail/Alpha-Taiwan/RE160F-40E3-20A-24P/?qs=yA6kp8fx8Y7zlmuFqx9z8g%3d%3d

Many greets,

Peter

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I'm too lazy to open up the case once again, I'm not sure what encoder my device has. But I'm pretty sure it's built from a complete kit, so whatever those were using?

OTOH I have been only recently taken this out for a test drive, and it seems today after some tweaking it's better (in the past it was really unusable), so maybe it's just a problem with non-use from the previous user and me? I will see about this...

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  • 2 weeks later...
  • 7 years later...

I have just finished building my MB6582 and my non-detented Bourns PEC16-4020F-N0024 encoders are giving me these issues (wish I'd found this thread before!)

I don't really want to resolder all 14 of the encoders. From what I understand the latest version of the MB6582 firmware has some sort of debouncing built in, so there doesn't seem to be a simple software fix available.

Has anyone had any luck using capacitors to debounce them?

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Hi lifeglug,

Would be great if you could fix it electronically but I highly doubt that you'll get a common fix across the batch that could fix it for all encoders equally.  In my case desoldering was the only way and what I should have done from the beginning. I spent too long on "what if" and "how come" scenarios. I've since built a second mb6582 and had no problems at all.  It's sucks but it's the luck of the draw sometimes.  Pick your worst and just desolder that one.  That will prove the fix, 14 sounds like a lot of desoldering but like anything if you take your time you can be successful.  The feeling of getting it fixed almost makes it worthwhile! 

 

Cheers,

Arkay.

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You're laughing then.  The encoders are likely bunk anyway so you don't need to not destroy them. It's easy to cut the legs and desolder the remainder if the structural tabs aren't soldered. Clean up the holes with braid. And you'll be done in no time. Then you'll have a properly working instrument you can be proud of and use for the purpose intended.  Can see only good things coming from the decision :)

Good luck and let us know how it turns out.

Cheers,

Arkay

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