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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
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Posted: Fri Oct 09, 2009 6:24 am Post subject:
What about the CEM3396 dual DCO? Subject description: did anyone ever used it for a module? |
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hi all,
i searched the net but could not find anything along these lines, so did anyone of you did this? _________________
cheers,
matthias
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Big Boss at fonitronik
Tech Buddy at Random*Source |
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bugbrand
Joined: Nov 27, 2005 Posts: 846 Location: Bristol, UK
Audio files: 1
G2 patch files: 1
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Posted: Fri Oct 09, 2009 8:03 am Post subject:
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Heya - I got a few of these quite a few years back and hunted around for tips on use - didn't find much (I think there's an old post here from me..)
I did a bit of testing, but didn't get much working properly (but didn't really understand things at the time!)
The Cheetah MS6 and Oberheim Matrix6 & 1000 all seemed to use the 3396 - here's a page with the MS6 schematic, though getting thoughts out of it may take some head scratching!
http://www.butoba.net/homepage/ms6.html
Here's another interesting looking topic with some potentially useful info
http://www.midibox.org/forum/forums.html/topic,13770.0.html
Let us know if you figure anything much - ever year or so I remember I have these chips and kick myself (but then don't do much to remedy the situation!) _________________ http://www.bugbrand.co.uk
http://www.bugbrand.blogspot.com |
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Dego
Joined: Apr 22, 2008 Posts: 139 Location: Sweden
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Mooger5
Joined: May 02, 2007 Posts: 199 Location: Portugal
Audio files: 8
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Posted: Fri Oct 09, 2009 1:49 pm Post subject:
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The 3396 is more versatile than the 3394 and available through http://www.maad.net/ms6/ but the call for a microprocessor for selecting the waveforms instead of CV made me choose the 94, as I don´t know enough about digital.
However, after studying other synths´ service manuals I´m thinking it´s possible to select the waveforms by means of a simple logic circuit and a rotary encoder. |
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jojjelito
Joined: Jun 27, 2007 Posts: 50 Location: Stockholm, Sweden
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Posted: Fri Oct 09, 2009 2:44 pm Post subject:
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Alas, I've made no further progress with the 3396 as life as such and my project backlog ate a fair bit of my time. Still, there's some heavy lifting to do since the schematics for the synths that are using this are barely legible. Maybe there's some good stuff in Barry Klein's Electronic Music IC Databook?
Anyway, it would be nice to cook something useful but don't expect quick results. You could fake the timing signals with a square wave from a VCO for starters. But there's lots more to do... |
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
Audio files: 23
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Posted: Fri Oct 09, 2009 3:24 pm Post subject:
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thank you for all the replies so far. good stuff.
olga42 wrote: | You could fake the timing signals with a square wave from a VCO for starters. But there's lots more to do... |
i though of using a PIC!? what do you think? _________________
cheers,
matthias
____________
Big Boss at fonitronik
Tech Buddy at Random*Source |
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jojjelito
Joined: Jun 27, 2007 Posts: 50 Location: Stockholm, Sweden
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Posted: Fri Oct 09, 2009 3:49 pm Post subject:
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fonik wrote: | thank you for all the replies so far. good stuff.
olga42 wrote: | You could fake the timing signals with a square wave from a VCO for starters. But there's lots more to do... |
i though of using a PIC!? what do you think? |
The thinking was along the lines of DCOfreq=SquareWavefreq so that one could just fake it in order to get something, anything out of the chip. Unfortunately I was off. It holds true, but that's not all that's needed. The waveshape will be crazy. PP1: "The frequency of these waveforms is equal to the inpuit digital signal". This chip is all about a VF converter and waveshapers in addition to timing in order to make things interesting.
So PIC it is. MIDIbox-ish unless you want to deal with the CharlieFoxtrot that involves getting a PICboard up and running with bootloader, your written from scratch software and all that jazz. Then again, it all depends on how complicated you want your app to be. The 9090 drum module has a small, no nonsense app that runs just fine. However MIDIbox gives you lots for free (with certain limitations).
*Edited after checking assumptions and memory vs data sheets* |
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
Audio files: 23
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Posted: Fri Oct 09, 2009 4:12 pm Post subject:
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a little bit complicated, i knew. the datasheet sais: '... as the frequency is changed, the waveform control voltage must be changed proportionally...'.
i fear it will not be done this or next year _________________
cheers,
matthias
____________
Big Boss at fonitronik
Tech Buddy at Random*Source |
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Mooger5
Joined: May 02, 2007 Posts: 199 Location: Portugal
Audio files: 8
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Posted: Thu Oct 15, 2009 7:40 pm Post subject:
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olga42 wrote: |
The waveshape will be crazy. PP1: "The frequency of these waveforms is equal to the inpuit digital signal". This chip is all about a VF converter and waveshapers in addition to timing in order to make things interesting.
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Hi, what if you just let the waveshape be crazy everytime the pitch changes? I was thinking the output might not be useful as tone generator but probably interesting as modulation source |
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jojjelito
Joined: Jun 27, 2007 Posts: 50 Location: Stockholm, Sweden
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Posted: Fri Oct 16, 2009 4:06 am Post subject:
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Mooger5 wrote: |
Hi, what if you just let the waveshape be crazy everytime the pitch changes? I was thinking the output might not be useful as tone generator but probably interesting as modulation source |
By all means, try it out! The crazyness will be static, not only when the frequency changes. It will make a fun, chaotic LFO for sure.
The trouble is that there is a complicated set relationship between the input square wave frequency and what one must do the waveform control voltage in order to keep the waveshape under control irregardless of frequency. So, it may not be musically useful as a VCO sans microprocessor control. |
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Mooger5
Joined: May 02, 2007 Posts: 199 Location: Portugal
Audio files: 8
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Posted: Fri Oct 16, 2009 2:38 pm Post subject:
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Ah, thanks. I´m commited to the CEM3394 which I think should be easier to "debug", so right now this is only food for thought
You know, the last firmware version for the Matrix 1000 is available online. I saw the file in a Yahoo Group. I can find it for you if you want. The microprocessor is a Motorola MC68B09P. I can´t read code, but I figure the file might be useful |
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iorobyy
Joined: Sep 26, 2005 Posts: 65 Location: Italy
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Mooger5
Joined: May 02, 2007 Posts: 199 Location: Portugal
Audio files: 8
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Posted: Sat Oct 24, 2009 1:17 pm Post subject:
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The 3396 is much better featured than the 94, hence the matrix modulation capabilities in the Obies.
In addition to the 24dB-only filter in the 94, a drawback is there is no direct VCO output...
So you took a step further by ditching the DCO issues in the 96 and applied external oscillators to take advantage of the existing waveshapers? |
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iorobyy
Joined: Sep 26, 2005 Posts: 65 Location: Italy
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Posted: Sun Oct 25, 2009 3:31 am Post subject:
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the 3396 as the 94 was intended as a "1chipsynth" the 94 was the cv version
the 96 was the digital drive version however both was intended for ibrid (analog/digital) applictions...as the matrix1000 or cheetah , curtis was a devil!
However the possibilities of 94 and 96 are enormous , you really could
to build a almost single-chip-synth if you really want.
The advantage of 96 is that you could drive it by an existing vco or build a
1voctave very simple square vco (ne566!) you'll divide the output with a 4024 divider (see neil jonhson site or other clock divider) then u'll drive the cem3396 with the octaved clock.
You could obtain a fully 2 voice with very complex shape 1v/octave vco with the advantage of the compltely exact octaves obtained with the 4024...the vcf (if you dont want use it set'it fully open or with a timbre that you prefere) - a VCA (idem if you dont want to use it ) ....so ...i hope i was clear...no? arghhh...try to buy a 96 and go mad with your protoboard!!! |
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Mooger5
Joined: May 02, 2007 Posts: 199 Location: Portugal
Audio files: 8
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Posted: Sun Oct 25, 2009 9:24 pm Post subject:
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iorobyy wrote: |
[...] ....so ...i hope i was clear...no? arghhh... |
Oh yes, no problems with that, it´s just my knowledge of electronics is still limited. Especially when it comes to logic circuits, of which I only have a general idea of the possibilities, so some simple things aren´t yet so obvious.
I´ll have to ask the opposite of the usual question: you made the PCB - would you mind sharing a schematic? |
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monokinetic
Joined: Aug 01, 2006 Posts: 100 Location: prague
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Posted: Mon Oct 26, 2009 2:31 am Post subject:
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Hi,
I'm not 100 percent sure how useful this info could be, but just in case you haven't come across it:
On the midibox forum recently there was some discussion about using the cem3396. The thread is here:
http://midibox.org/forum/forums.html?/topic/12863-mios-project-oberheim-m1000-xpander-pcb-traces-uploaded/
Although the main theme is about expanding the Matrix 1000, there is some interesting info on driving the 3396 (a bit over my head to be honest, but it may be of use!)
HTH
David |
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bod
Joined: Apr 28, 2009 Posts: 148 Location: Glasgow
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Posted: Mon Oct 26, 2009 5:40 am Post subject:
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i have a nasty habit of buying and hoarding these types of chips for later use, but i've not come across the 3396 yet, and i looks very interesting! i like the sound of using another vco to clock it, but i recon you might be able to something like arduino to interface this quite easily and use it over midi.
have you done anything with your 3394's mooger5? i have a couple of these i was thinking about turning into a little diy keyboard synth somehow. nothing too fancy, AR, LFO, noise, the 3394 and a 3 octave keyboard.
well, thats if i ever finish everything else on the bench just now!!! |
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iorobyy
Joined: Sep 26, 2005 Posts: 65 Location: Italy
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Posted: Mon Oct 26, 2009 11:02 am Post subject:
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wow guys , a 30 years old tecnology could be a problem for us??
Think simply! analogic is simple and efficent ! this is one of the advantages of 3396 and 3394.
You could complicate your life with arduino or midibox intefaces or simply
think an analogic approach...i repeat...cem3396 could work also with common potentiometers 0-5V or cv signals and need only a squarewave for to be drived...read datasheet and made your experiments.
The pcb i posted have no schematic , i have a handmade layout only , if someone is interested i'll try to take a picture.
I have also a pcb for the cem3394 but also here no layout files...only paper....i'm a big cazzone!
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Mooger5
Joined: May 02, 2007 Posts: 199 Location: Portugal
Audio files: 8
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Posted: Mon Oct 26, 2009 9:38 pm Post subject:
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bod wrote: | i have a nasty habit of buying and hoarding these types of chips for later use, but i've not come across the 3396 yet, and i looks very interesting! i like the sound of using another vco to clock it, but i recon you might be able to something like arduino to interface this quite easily and use it over midi.
have you done anything with your 3394's mooger5? i have a couple of these i was thinking about turning into a little diy keyboard synth somehow. nothing too fancy, AR, LFO, noise, the 3394 and a 3 octave keyboard.
well, thats if i ever finish everything else on the bench just now!!! |
I don´t have the chips. I had a Paypal dispute with Chipforbrains after waiting for a month, and opted for the refund. Better this way I think, still have a million projects to finish. If there was something like Procrastinators Anonymous I´d join them. Erm... one day... |
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Mooger5
Joined: May 02, 2007 Posts: 199 Location: Portugal
Audio files: 8
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Posted: Mon Oct 26, 2009 10:03 pm Post subject:
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iorobyy wrote: | wow guys , a 30 years old tecnology could be a problem for us??
Think simply! analogic is simple and efficent ! this is one of the advantages of 3396 and 3394.
You could complicate your life with arduino or midibox intefaces or simply
think an analogic approach...i repeat...cem3396 could work also with common potentiometers 0-5V or cv signals and need only a squarewave for to be drived...read datasheet and made your experiments.
The pcb i posted have no schematic , i have a handmade layout only , if someone is interested i'll try to take a picture.
I have also a pcb for the cem3394 but also here no layout files...only paper....i'm a big cazzone!
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But that´s fantastic! I think you have just debunked a historical myth Post some audio files and I bet there´ll be a million eyes and ears!
I still got a 96 left from my M1000 "survival kit". I´ll try it one day.
Cheers! |
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bod
Joined: Apr 28, 2009 Posts: 148 Location: Glasgow
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Posted: Tue Oct 27, 2009 12:05 pm Post subject:
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iorobyy wrote: | wow guys , a 30 years old tecnology could be a problem for us??
Think simply! analogic is simple and efficent ! this is one of the advantages of 3396 and 3394.
You could complicate your life with arduino or midibox intefaces or simply
think an analogic approach...i repeat...cem3396 could work also with common potentiometers 0-5V or cv signals and need only a squarewave for to be drived...read datasheet and made your experiments.
The pcb i posted have no schematic , i have a handmade layout only , if someone is interested i'll try to take a picture.
I have also a pcb for the cem3394 but also here no layout files...only paper....i'm a big cazzone!
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i got into synth diy because i like making things difficult for myself! but you're right, and i love the idea of the 566! mmm.... i'm going to have to clear some space to try this out.
thats not good about the chipforbrains situation mooger5, i have an order with them just now. hope i get it through ok.
cheers,
bod. |
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magman
Joined: Feb 04, 2009 Posts: 363 Location: Liverpool, UK
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Posted: Tue Oct 27, 2009 12:16 pm Post subject:
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iorobyy wrote: | The pcb i posted have no schematic , i have a handmade layout only , if someone is interested i'll try to take a picture. |
I would definitely be interested in a picture or scan of the circuit diagram you worked out iorobyy, as it could prevent some re-discovery of things you've already worked out.
I've got a couple of 3396's sat on my desk at them moment and it is one of my projects for this year to get them working as stand alone modules (I've also got a 3340 and some 3310's that are also going to get modularised some time this year, with a bit of luck).
Regards
Magman |
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Mooger5
Joined: May 02, 2007 Posts: 199 Location: Portugal
Audio files: 8
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Posted: Tue Oct 27, 2009 4:44 pm Post subject:
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bod wrote: |
thats not good about the chipforbrains situation mooger5, i have an order with them just now. hope i get it through ok.
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Well, it was the first time I ran into something like this, hence why I´m mentioning. The listings on Ebay and Paypal for the same item didn´t match and I was getting messages like this about something I had paid last month:
Quote: | This listing (290322405950) has been removed, or this item is not available.Please check that you've entered the correct item number
Listings that have ended 90 or more days ago will not be available for viewing. | So opening a dispute was the only means to find out what was going on. Cy said he didn´t see my payment and appologized. I guess these things happen. For peace of mind check the item numbers in your accounts and invoices.
Good luck. |
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iorobyy
Joined: Sep 26, 2005 Posts: 65 Location: Italy
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iorobyy
Joined: Sep 26, 2005 Posts: 65 Location: Italy
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Posted: Sun Nov 29, 2009 6:25 am Post subject:
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circuit in progress picture + cheese paper studies
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