nebula Posted October 2, 2007 Report Share Posted October 2, 2007 You know, that Juno filter sounds really sweet, thick, lush. It will self-oscillate but in a remarkably musical way. It kinda got me thinking ...You may already know that each voice on the Juno-106 uses a custom Roland IC called the 80017A, which is essentially a combined VCF and VCA. The reason many know that is because the IC is very prone to failure, and when it goes it causes the dreaded "I lost one of every six notes" syndrome. Roland no longer makes them, but in an effort to "save the Junos", some people have tried to clone the long since discontinued Roland IC. If I'm to believe everything I read, one guy has actually managed to get close enough that you can't hear a difference, using readily available parts. With the Juno-106 service manual it should be a cakewalk to figure out the pinning on an 80017A.So ... you could probably stick 8 of these filters on a board with an AOUT ... filter each SID from your MB-6582, or maybe use it as the basis of a Juno-106 clone. Quote Link to comment Share on other sites More sharing options...
opkod Posted October 2, 2007 Report Share Posted October 2, 2007 look at this vcf/vca clone : http://www.analoguerenaissance.com/D80017/3 ;) Quote Link to comment Share on other sites More sharing options...
ilmenator Posted October 2, 2007 Report Share Posted October 2, 2007 At 40,- Euros each (that means per voice :o) this is ridiculously expensive. It's not a DIY project, and although I respect this guy's work I would not try to incorporate such a thing into an otherwise completely DIY project.Best regards, ilmenator Quote Link to comment Share on other sites More sharing options...
nebula Posted October 2, 2007 Author Report Share Posted October 2, 2007 look at this vcf/vca clone : http://www.analoguerenaissance.com/D80017/3 ;) That's the one I was talking about. I inadvertently linked to his older site. Quote Link to comment Share on other sites More sharing options...
nebula Posted October 2, 2007 Author Report Share Posted October 2, 2007 At 40,- Euros each (that means per voice :o) this is ridiculously expensive. It's not a DIY project, and although I respect this guy's work I would not try to incorporate such a thing into an otherwise completely DIY project.Best regards, ilmenatorGoing rate for CEM3378 chips is about $10 each. People in this community use them rather than make filters using discrete components, which could theoretically be a bit cheaper. Oh and don't forget, lots of us have ponied up $20 each for SIDs, and plan to put 8 in a box!While it's completely subjective, I will step up to bat and say that the filters on Roland's classic Junos are among the sweetest sounding in synth history. Quote Link to comment Share on other sites More sharing options...
Jaicen Posted October 2, 2007 Report Share Posted October 2, 2007 I don't know if it's important, but the Juno filter chips were used in a few of Roland's products. Essentially, it's based on the Moog filter design, using diodes instead of a transistor ladder. Personally, I find Roland filters to be more musically useful than Moogs anyway. You can make a Jupiter or SH09 (discrete filter I know) sit much easier in a mix than something like a Minimoog. Quote Link to comment Share on other sites More sharing options...
stryd_one Posted October 2, 2007 Report Share Posted October 2, 2007 Going rate for CEM3378 chips is about $10 each.Huh where? Quote Link to comment Share on other sites More sharing options...
Wilba Posted October 4, 2007 Report Share Posted October 4, 2007 from: http://www.analoguerenaissance.com/D80017/3Stupid Question FeeFrom now on I charge 10EUR for every question that people ask me by mail that is already answered on this page. I am tired of answering the same questions over and over and over again. This keeps me from doing electronics. Maybe it's wrong of me to say this, but what an asshole. If you're going to charge 40EUR and make money off something like this, stop complaining and answer your potential customer questions, regardless of whether they were answered already or not. If someone asks me a question about MB-6582 that is already answered in the wiki etc. I direct them to it. If I got 10EUR every time, I'd have enough to fly to Munich and jam with TK for a week. *whack* Quote Link to comment Share on other sites More sharing options...
Sasha Posted October 4, 2007 Report Share Posted October 4, 2007 ...If I got 10EUR every time, I'd have enough to fly to Munich and jam with TK for a week. ;D ;D ;D I understand the guy`s frustration, but when it is commercial product it is OK to listen to most stupidest questions you can imagine. It is obvious that this guy rather do only electronics, but than he needs to let others to take care of commercial things and customer care. I hate to deal with customers myself... but as it is my job I need to be nice even I would rather tell them to go to hell. Customer is always right. I hate it, but is IS truth if you want to earn money. Quote Link to comment Share on other sites More sharing options...
DrBunsen Posted October 4, 2007 Report Share Posted October 4, 2007 You know, he's got some pretty good close-ups of his boards there... 8) Quote Link to comment Share on other sites More sharing options...
Jaicen Posted October 4, 2007 Report Share Posted October 4, 2007 True, but not quite good enough. There are no markings on the IC's, and the board is double sided... Quote Link to comment Share on other sites More sharing options...
DrBunsen Posted October 4, 2007 Report Share Posted October 4, 2007 Surely between all of us we could reverse engineer something? I could donate a working one to the cause. It's not like my MKS7 is doing anything right now :( Quote Link to comment Share on other sites More sharing options...
Ashiman Posted October 4, 2007 Report Share Posted October 4, 2007 LOL!besides ppl assembling groupbuy for CEM3372 filterchip on synthdiy, the one used in Oberheim Xpander , giving state variable LPHPBP at the same time Quote Link to comment Share on other sites More sharing options...
stryd_one Posted October 5, 2007 Report Share Posted October 5, 2007 I got a datasheet here with my stack of 3372s and it says lowpass only :( I know you can do tricks to turn lowpass into high, but that means no resonance. I tried to find any mention of this project, to see what the deal is, but cant :( Quote Link to comment Share on other sites More sharing options...
nebula Posted October 5, 2007 Author Report Share Posted October 5, 2007 the Juno filter chips were used in a few of Roland's products.Best I can tell: the Juno-106, the MKS-30 "Planet S", and the MKS-7 "SuperQuartet". Are there more?You learn something every day: I always thought the MKS-30 was a rackmount JX-3P, since it has an identical parameter set and uses the PG-200 programmer. But the JX-3P uses discrete filters (based around IR3109) while the MKS-30 uses 80017 chips.You can make a Jupiter or SH09 (discrete filter I know) sit much easier in a mix than something like a Minimoog. Jupiter-6 and Super Jupiter use CEM filters. Quote Link to comment Share on other sites More sharing options...
Ashiman Posted October 5, 2007 Report Share Posted October 5, 2007 probably the best explanation can be obtained by searching for SSM2040 http://www.siliconbreakdown.com/msl/chip.htmloh and if you check the MOTM partlist for the discrete 2040, they use the CA3086... e(r v r s n g n r pl s) ;D Quote Link to comment Share on other sites More sharing options...
stryd_one Posted October 5, 2007 Report Share Posted October 5, 2007 Ahh the poles are exposed at the cap pins, cool. Thanks PB! Quote Link to comment Share on other sites More sharing options...
Jaicen Posted October 5, 2007 Report Share Posted October 5, 2007 The early MKS-30's did indeed use the IR3109, also used in the venerable GR-300), and Juno 6 and 60. However when Roland re-used the architecture and indeed boards for the GR-700 and GR-77b they switched over to the same chips as used in the Juno 106, HS106 and related racks. I think it can be found in some other less well known products like the VK's, but I can't be sure. Those are the only ones that I know feature this chip for sure. EDIT: Check out this page, you can see that the IR3109 is in a heap of old roland stuff:http://analog.no/rolandcustom.htm Quote Link to comment Share on other sites More sharing options...
DrBunsen Posted October 5, 2007 Report Share Posted October 5, 2007 I'm searching: I'm looking to restore a Juno 106 (MKS7 - the rackmount version), rather than a general purpose filter for MB projects. Though if that becomes an option, sweet.We've been discussing in Chat the possibility of reverse engineering an 80017a clone and open sourcing the design. That would give hackers the option of restoring their dead Junos at a lower price (and more labour) than the available substitutes.I just found this most interesting image in an article on Matrixsynth.As you can see, there are separate I/O pins for the VCF and VCA stages, for both signal and control. The VCF is a Roland IC?* called an IR3109 and the VCA is BA662* So in essence they're two completely separate blocks, which breaks the cloning problem down into two parts: cloning the IR3109 and the BA662. Or alternatively: making a socketed adapter board that can take SSM ICs for VCF and VCA.There are trimpots on the mainboard which allow you to fine tune the sound so each voice matches.I also found a block diagram for the insides of the chip here*according to this they are surface mount versions called A1QH800170 and uPC1252H2 BA662===============================================================Other links and snippets:A good 80017a replacement walkthroughGuitar Synth Repair Tips has pdf links for calibration, schematics inc 106, MKS30To check which voice IC is bad, do this:This guy cut open an 80017a and had a look :)Analog Workshop:my drawing of the Roland SH-101 VCF.This circuit uses the Roland IR3109 IC ...The VCF could also be easily made with two LM13700 or NJM13600 IC's instead.*From Harmony Central forums:Isn't the JP8 filter a Roland IR3109, making it an IC not discrete?it's not a single IC. it's a name for the whole circuit. / they used several transconductance amplifiers (BA662) or OTAs, custom made for Roland for both LPF and HPF...about JP6/MKS80 - it does again say it uses IR3109 - but it sounds soo different. they were using, not only different series OTAs, but also they used a 4 x 6dB configuration to get 24dB/Octave - resulting in less warm and drier reonance etc.. Quote Link to comment Share on other sites More sharing options...
DrBunsen Posted October 5, 2007 Report Share Posted October 5, 2007 cloning the IR3109There's an attempt here (badly translated from French partly by Google, partly by me)Both component are LM13700. They replace the original BA662 which are very hard to find but I think that if I remake it I will replace them with BA6110 which are more faithful than the LM13700. I have this schematic which shows all the connections but misses the values of certain resistors and of a condo (capacitor?). In fact I based it on the diagram of the sh101 which is identical; so if somebody has more information that would be nice. Quote Link to comment Share on other sites More sharing options...
Wilba Posted October 5, 2007 Report Share Posted October 5, 2007 I got a datasheet here with my stack of 3372s and it says lowpass only :( I know you can do tricks to turn lowpass into high, but that means no resonance. I tried to find any mention of this project, to see what the deal is, but cant :(http://m.bareille.free.fr/modular1/vcf_multimode/extrapole.htm Quote Link to comment Share on other sites More sharing options...
Jaicen Posted October 6, 2007 Report Share Posted October 6, 2007 Ok, this I think is looking possible. The 80017 contains a pair of BA662's, which are essentially just op-amps that make up the VCA. It's the same chip used in the 303, and it is available, but there are cheaper alternatives like the BA6110. Basically, it's an amp whose gain is dependant on the current fed into it's control input, but that's not really important to know, the basic design can be ripped straight from the 303! With regards to the IR3109, that is in fact a complete on-chip filter. Just the caps and a few resistors are external, which allow you to tune it to a specific range. Basically, I wouldn't be surprised if it's similar to the CEM chips used in the Jupiter6. If you were happy to use a work-a-like VCF/VCA combo, you could easily sub in any number of designs in there. How about if it were possible to find som SMT transistors and stick in a Moog filter and BA6110 VCA ;)EDIT: After a little more searching, I had time to check out the link that Playb0$$ posted. It seems that it would be possible to make a very cheap discrete version of the SSM2044 chip using this schem: http://jhaible.heim.at/tonline_stuff/jh2040.gifIt would need something like 4 3086's for a four pole filter, but that would give matched transistors so it would be very easy to build. My guess is that the Analogue Reneissance design uses something like this. Quote Link to comment Share on other sites More sharing options...
stryd_one Posted October 6, 2007 Report Share Posted October 6, 2007 Wilba: Scroll up dude we did that already ;) Jai: I don't think there's much point cloning them when they're so readily available at such a low price ... Quote Link to comment Share on other sites More sharing options...
Wilba Posted October 6, 2007 Report Share Posted October 6, 2007 Wilba: Scroll up dude we did that already ;) I'm scrolling, I don't see how I'm duplicating anything...I'm going to fork off a new thread about a CEM3372 filter module. Quote Link to comment Share on other sites More sharing options...
Jaicen Posted October 6, 2007 Report Share Posted October 6, 2007 Perhaps you're right Stryd, but I was thinking that rather than just clone the SSM2044, maybe it would be interesting to build a VCF and VCA onto a single chip like the Analogue Solutions jobbie, that can be used for Midiboxing. I was thinking that a clone of the TB's VCA and ladder filter, on-chip would be awesome! Also, if the pinouts were compatible, it would then be a drop-in replacement for old Juno chips. Imagine a Juno with a discrete moog-style filter! I don't know how much height there is available inside the 106, but you could easily fit a 2" PCB into the Juno 6. That said, I wouldn't mind a (or a even a pair) of SSM2044's if anybody was interested in selling some. I can't really afford to fork out for those 12 on fleabay right now, (MB6582 is bankrupting me!). Quote Link to comment Share on other sites More sharing options...
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