rootshmk Posted January 10, 2014 Report Share Posted January 10, 2014 Hello everyone I have the problem that my 8 SID synth somehow turns the individual stereo out into two identical mono signals, both containing L and R. The builder says that it was a first generation build. Not sure if it was built like this or if these are transport defects. It behaves exactly the same for all 4 individual outs, and everything else seems to work fine on the synth. Except the passive mixer out does not work at all either. Any hint would be highly appreciated. I am a bit puzzled that all 4 work exactly the same (wrong) way. If there wasn't an obvious other fault with the mix out I would even think it is user error on my side (I tried for hours though and can modulate the filters of both chips separately, for example, and both modulations can clearly be heard, but always on both speakers). Quote Link to comment Share on other sites More sharing options...
Altitude Posted January 10, 2014 Report Share Posted January 10, 2014 (edited) that's how it's supposed to work. One SID per channel The passive mixer only works if nothing is connected to the main outs. Edited January 10, 2014 by Altitude Quote Link to comment Share on other sites More sharing options...
rootshmk Posted January 10, 2014 Author Report Share Posted January 10, 2014 that's how it's supposed to work. One SID per channel The passive mixer only works if nothing is connected to the main outs. Thank you for the answer, Altitude. If I understand correctly it is supposed to work like this: SID1 = L SID2 = R Instead my unit does: SID1+2 = L SID1+2 = R Identical signal in both channels. All 4 direct outs behave the same. It is like in mono mode but *both* SIDs (?). When trying the passive mixer I do not connect anything else. Quote Link to comment Share on other sites More sharing options...
Shuriken Posted January 11, 2014 Report Share Posted January 11, 2014 If you are sure about this, then i think you should open the box up. Then post a highres photo of the top and bottom side of the mainboard. Quote Link to comment Share on other sites More sharing options...
Altitude Posted January 11, 2014 Report Share Posted January 11, 2014 +1, sounds like something is not wired correctly. Does this have the feedback pots? Quote Link to comment Share on other sites More sharing options...
rootshmk Posted January 11, 2014 Author Report Share Posted January 11, 2014 (edited) Many thanks for taking the time guys. I made some pics, hope you can see all you need. Direct links to the real size pics: http://imageshack.com/a/img716/4866/le62.jpg http://imageshack.com/a/img826/689/1gju.jpg http://imageshack.com/a/img22/2361/nc1f.jpg http://imageshack.com/a/img546/9282/451n.jpg http://imageshack.com/a/img547/216/jo1u.jpg Edited January 11, 2014 by rootshmk Quote Link to comment Share on other sites More sharing options...
Shuriken Posted January 11, 2014 Report Share Posted January 11, 2014 Besides cutting a few corners here and there i cannot see something obviously wrong with this build. The only modifications i see are in the power section and in the lcd connector. Quote Link to comment Share on other sites More sharing options...
sneakthief Posted January 11, 2014 Report Share Posted January 11, 2014 Are those mono potentiometers instead of stereo ones? That could explain it - because it looks like SIDs 1 and 2 are connected together at the pot and being summed to both left and right. Quote Link to comment Share on other sites More sharing options...
rootshmk Posted January 12, 2014 Author Report Share Posted January 12, 2014 Stupid question: how do I check this? That would certainly explain it.. Quote Link to comment Share on other sites More sharing options...
Altitude Posted January 12, 2014 Report Share Posted January 12, 2014 (edited) yep, mono pots are your problem. They're supposed to be dual like this:http://www.mouser.com/catalog/specsheets/TW-700150.pdf Edited January 12, 2014 by Altitude Quote Link to comment Share on other sites More sharing options...
Shuriken Posted January 12, 2014 Report Share Posted January 12, 2014 (edited) yep, mono pots are your problem. They're supposed to be dual like this:http://www.mouser.com/catalog/specsheets/TW-700150.pdf Are you sure these are the correct ones? I thought the MB6582 required pots with a 4mm shaft. Or is that just on my backpanel? Edited January 12, 2014 by Shuriken Quote Link to comment Share on other sites More sharing options...
Altitude Posted January 12, 2014 Report Share Posted January 12, 2014 That's what I used and they are fine. Flatted D is 6mm, I dont think I've ever seen 4mm shafts Quote Link to comment Share on other sites More sharing options...
Shuriken Posted January 12, 2014 Report Share Posted January 12, 2014 (edited) These are 4mm shafts. The 6mm ones don't fit my panel. Edited January 12, 2014 by Shuriken Quote Link to comment Share on other sites More sharing options...
Altitude Posted January 12, 2014 Report Share Posted January 12, 2014 (edited) woah, those are huge, that looks like a 6mm shaft though.. The holes are for a M7 threaded part Edited January 12, 2014 by Altitude Quote Link to comment Share on other sites More sharing options...
rootshmk Posted January 12, 2014 Author Report Share Posted January 12, 2014 You guys have no idea how much YOU ROCK!!! Thank you so much. I just unplugged the attentuators and everything is as it should. When I connect *one* SID back to the attentuator, this channel also appears on the passive mix out. Just on the L or R of course depending on which SID is connected. I assume once they are properly wired this will work as expected, too. Best of all: I can use it immediately just w/o feedback. YAY! Should even be capable with my basic soldering skills to swap these out myself. I also removed the (very noisy) ventilator, reading a thread here I think it should be ok (studio use only, no hot venues etc). Unless someone has made bad experience meanwhile, if so please say so. Well, if I ever can do you a favour, please send me a PM (no clue, mix a track with nice outboard? "master" it or provide samples of mostly analoge synths or process stuff, whatever). Thanks a lot. Quote Link to comment Share on other sites More sharing options...
Shuriken Posted January 12, 2014 Report Share Posted January 12, 2014 You have the 6582 SID in there. Those don't run so hot. But just to be sure, you could put on some heatsinks. Quote Link to comment Share on other sites More sharing options...
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