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HybrisBehemoth

MB 6582 Final troubleshooting; encoders and presets

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So I finally got around to finishing my MB6582. Just some final troubleshooting left (I hope):

All the encoders have some random behavior to them. They will be working fine and then suddenly the value will jump a couple of steps in a random direction, even when I'm just making a small adjustment. As I said this goes for all of them, including the one where I didn't remove the detent.

Uploaded the standard patches but some of them are acting weird. Some are fine, some wont make any sound and some are very quiet so that I have to crank the volume to hear them. I only have one 8580 installed and I did change the setting to mono in the ensemble menu.

Suggestions are highly appreciated :)

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I believe the standard patches are set up for 6581 SIDs. There are a few settings changes you’ll want to make in the ensemble menu before they’ll work well for 8580/6582s. (Also, I think some of the patches just have the filter closed by default.)

As for the encoders... What encoders are you using? IIRC, some folks have had trouble with the “acceleration” code for the encoders. Try searching the forum for more info. Since you’re having problems with all of them, it points to either a problem with the part you’ve installed or the software.

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I'm using these Bourns encoders:

https://no.mouser.com/ProductDetail/652-PEC16-4220FN0024

Chose them since they are highly recommended in the MB6582 control surface BOM:

http://www.midibox.org/dokuwiki/doku.php?id=wilba_mb_6582_control_surface_parts_list

But now I'm reading posts indicating that a lot of people have had trouble with the Bourns encoders. Maybe they shouldn't be listed as highly recommended in the BOM ...

Been searching and reading a lot about this but there doesn't seem to be a solution other than de-soldering and buying other encoders. :( 

 

Set my filters to the recommendations for 8580 found here (range 0-600 Log: on): 

http://ucapps.de/midibox_sid_manual_e.html 

This didn't make any difference though; most of the patches are still really quiet. Notably whenever i tweak filter setting the range is still the full 0-FFF, and not the 0-600 that I set. Are there any other changes to be made when using 8580s?

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I used those same encoders and my MB-6582 is working fine, so I wouldn’t jump to desoldering just yet.

The range shown in the filter menu will always be 0-FFF, this way you always have the same number of steps in the filter adjustment even if the internal parameter is set to a reduced range.

Instead of relying on the default patches to determine whether things are working correctly, I suggest setting up some patches from scratch.

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Posted (edited)

Are you sure your SID is at full health?

I've got a 6581 with close symptomes but this shouldn't explain the encoders behavior...

Edited by Noise-Generator

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Ah. So even if the menu goes from 0-FFF, FFF would represent 600 if I have set 600 as max? Because my filters only seem to react roughly in the 0-600 range (nothing changes between 600-FFF) even if max is set to 600. Does that indicate a defective filter then?

Not completely confident about the health of my SID (ebay).

Did you use the "standard" setup_mb6582.hex when you got your Bourns encoders working? Should I look into any settings or other firmware?

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3 hours ago, HybrisBehemoth said:

Ah. So even if the menu goes from 0-FFF, FFF would represent 600 if I have set 600 as max?

Pretty sure, yes.

3 hours ago, HybrisBehemoth said:

 Because my filters only seem to react roughly in the 0-600 range (nothing changes between 600-FFF) even if max is set to 600. Does that indicate a defective filter then?

Not sure tbh, never used a busted SID. There’s always a good chance it’s an issue with how you have it patched—always tough to tell when you power up a DIY project for the first time, whether it’s busted or whether you have to learn how to use it. OTOH, eBay SIDs are notoriously sketchy, so who knows?

3 hours ago, HybrisBehemoth said:

Did you use the "standard" setup_mb6582.hex when you got your Bourns encoders working? Should I look into any settings or other firmware?

Pretty sure I did. But maybe there’s an acceleration/debounce setting in the firmware that I’m not remembering.

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Done some more testing tonight. All the patches that work normally either doesn't use the filters or use high pass filters only. All the other patches are really really quiet. If I crank the volume I can still hear them (barely among the noise from the SID). If I sweep the filters there are no smooth filter sweep. Instead sounds cut in and out suddenly. If I change filter mode to high pass the patch starts working normally and at normal volume (way louder!). The filter sweep is also much more smooth when in high pass mode.

I assume that this points toward broken filters in the SID. Anything else I should consider/try? Haven't tried switching filtering caps. But I think they should be fine.

 

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Posted (edited)

there are some conflicting values for the caps around I found - although the ones for MIDIbox SID usually seem to be the correct 22nf, I found places that said 220nf and was a bit confused (probably not but worth mentioning I thought.. I tried building a different SID project with the wrong caps and the behaviour was not far off this)

That behaviour does also sound really similar to what was happening with mine when I didn't have the log flag to "On", and I was convinced it was broken..... but you've tried that.

Can you try the SID in other socket of the first core? (can't actually remember if that works, but if it does it at least eliminates an issue with something around the socket)

 

Edited by the_duckchild

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It’s starting to sound (to me) like maybe the filter on your SID is blown. But as I understand it, blown filters are not nearly as common on 8580s as they are on 6581s, so I think it’s worth following duckchild’s advice and really double and triple checking that all your patch settings are correct and that your filter caps are the correct value and installed properly.

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Triple checked the caps. Even dug out another pair of different caps with same value and tried with those instead. Same result.

Sounds like a good idea to try in another socket. I'll just have to get a proper IC removal tool first. I really don't want to break the SID (any more that it might already bee). I actually ordered 4 8580s on meeblip. So hopefully, in not too long, I'll have some more to compare to.

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