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janvanvolt
Joined: Nov 24, 2005 Posts: 285 Location: Mainz, Germany
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Posted: Sat Oct 06, 2007 5:46 pm Post subject:
Re: 8038 VCO PCB layout for press'n'peel blue Subject description: any interest? |
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The current version does work with an 8038 ? I am a bit puzzled as you speak about various chips for the core ...
(and no, i have not yet received my copy of the vco cookbook) |
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
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Posted: Sun Oct 07, 2007 8:44 am Post subject:
Re: 8038 VCO PCB layout for press'n'peel blue Subject description: any interest? |
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unit-sound wrote: | The current version does work with an 8038 ? I am a bit puzzled as you speak about various chips for the core ...
(and no, i have not yet received my copy of the vco cookbook) |
hi jan,
could you be a little more precise, please? or do you refer to another post/topic?
apologize me for being dense here... _________________
cheers,
matthias
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Big Boss at fonitronik
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
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Posted: Thu Oct 11, 2007 4:43 am Post subject:
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i'd recommended to STOP this project for a time. according to thomas' valuable comments concerning the cross-talk i will redesign the PCB layout hopefully next week.
see here:
http://electro-music.com/forum/topic-20737.html _________________
cheers,
matthias
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Big Boss at fonitronik
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
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softfin
Joined: Oct 11, 2006 Posts: 271 Location: Far in the north
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Posted: Mon Oct 29, 2007 5:23 am Post subject:
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fonik wrote: | i just finished a new layout. the two oscillators now only share the THAT IC which is a passive device anyway. the other parts of the oscillators are isolated from each other.
it is reviewed and triple checked (PCB against schematic) but i did not build it yet. so it's on your own risk!
www.modular.fonik.de/pdf/TH_dual8038VCOv2.pdf |
Thanks Fonik! I'm going to etch a pile of different boards probably some time next month and I'm planning to etch this one as well. I'll let you know how it turns out. |
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
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Posted: Mon Oct 29, 2007 5:24 am Post subject:
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you're the man, softfin. that's great. _________________
cheers,
matthias
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Big Boss at fonitronik
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etaoin
Joined: Jun 30, 2005 Posts: 761 Location: Utrecht, NL
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Posted: Wed Oct 31, 2007 1:00 am Post subject:
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Thanks Fonik!
Where did you get the THAT320? I can't seem to find that anywhere. _________________ http://www.casia.org/modular/ |
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
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softfin
Joined: Oct 11, 2006 Posts: 271 Location: Far in the north
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
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Posted: Mon Nov 12, 2007 1:38 am Post subject:
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sweet, looks pretty exceptional! hope it all works out all well... you are the prototyper for the new layout... _________________
cheers,
matthias
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Big Boss at fonitronik
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softfin
Joined: Oct 11, 2006 Posts: 271 Location: Far in the north
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
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Posted: Wed Nov 14, 2007 11:52 pm Post subject:
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softfin wrote: | Finished!
The Coarse Tune controls seem to interact somehow with each other... But not on all settings. Any guesses what could be the reason for this ? |
so the layout finally works? good to know! thank you so much, L.
concerning the interaction: the layout is actually divided in two layouts, one for each VCO, they even have their own power bus decoupling caps... sorry, no idea. wait! the ground network is not devided that strictly: especially the transistors share one ground node. don't know if that could cause a problem...
Quote: | Btw, I really like the character of the sine wave produced by this VCO, it's very soft, perhaps somewhat "wooden" sounding. |
indeed. did not look on the scope yet, though. _________________
cheers,
matthias
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Big Boss at fonitronik
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softfin
Joined: Oct 11, 2006 Posts: 271 Location: Far in the north
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Posted: Thu Nov 15, 2007 12:01 am Post subject:
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OK, ground remains shared between the two circuits, but I cut the connections for +-15 between the two VCOs and provided the +-15V separately to both sides.
Works fine now! |
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
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Posted: Thu Nov 15, 2007 12:12 am Post subject:
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yes, i got it. the layout provides just shared filters for the power rails (R1/R2). i will have to change this!
glad you solved it. _________________
cheers,
matthias
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Big Boss at fonitronik
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Luka
Joined: Jun 29, 2007 Posts: 1003 Location: Melb.
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numbernone
Joined: Aug 16, 2006 Posts: 477 Location: new york city
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Posted: Thu Feb 07, 2008 8:32 am Post subject:
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I have been poking at a layout for the 8038 myself, and may have to become the second tester for your design FONIK.
What level of Sine trimming is implemented on this layout?
And for my obvious and or dumb question...The layout currently on your site is the revised version??
Thanks |
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
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Posted: Thu Feb 07, 2008 2:31 pm Post subject:
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numbernone wrote: | What level of Sine trimming is implemented on this layout? |
none!
Quote: | The layout currently on your site is the revised version?? |
yes
i will hopefully do some scope screen shots on the weekend. _________________
cheers,
matthias
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numbernone
Joined: Aug 16, 2006 Posts: 477 Location: new york city
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Posted: Thu Feb 07, 2008 3:55 pm Post subject:
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Wow glad to hear you can get a decent sine without any of the add on circuitry, damn glad!!!
Great work Fonik! I think this will be the foundation of my 10,000 oscillator ANS meets Raymond Scott monstrosity (OK maybe 6). |
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numbernone
Joined: Aug 16, 2006 Posts: 477 Location: new york city
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softfin
Joined: Oct 11, 2006 Posts: 271 Location: Far in the north
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Posted: Mon Feb 25, 2008 12:57 pm Post subject:
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I finally put the dual 8038 vco in my modular.
It had been gathering dust for months because of lack of space in the modular, but now that I've got power in my 3rd cabinet, it was time to tune this vco, put it in the cabinet and test it further.
For some reason, I find it quite hard to tune it. After several hours of adjustments, I was able to achieve only about 4 octaves tracking.
In comparison, it took 10 minutes to get clean 6 octaves with a xr2206 osc.
Would appreciate any suggestions how to improve the tracking
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janvanvolt
Joined: Nov 24, 2005 Posts: 285 Location: Mainz, Germany
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
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Posted: Thu Apr 16, 2009 10:16 pm Post subject:
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i just wanted to let you guys know: the problem has been solved (some communication via email) and it is working fine now.
unit-sound was able to get 6 usable octaves from it - after 10min tuning using a tellun.com tuner!
i think i will throw away my module built from PCB version1 and rebuild it with the v2 board... _________________
cheers,
matthias
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Big Boss at fonitronik
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janvanvolt
Joined: Nov 24, 2005 Posts: 285 Location: Mainz, Germany
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Posted: Fri Apr 17, 2009 2:20 am Post subject:
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Sidenote: Make sure you use TL071/TL081 for U8/U9. I mistaken TL072 and all the TL's got very hot then. So if you experience this error, try to check the TL's first.
As fonik outlined: It's working perfect now. I used a .COM VCO and a octave switch to tune both OSCs. _________________ Homepage - http://www.czmok.de
My dIY - http://diy.czmok.de
Film/Music - http://gfm.me |
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kupfer_m
Joined: Oct 14, 2010 Posts: 48 Location: Belgium
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Posted: Thu Dec 02, 2010 8:02 am Post subject:
Where's the cookbook? |
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I have some 8038 chips laying around here and I'd like to build this VCO but I can't find the VCO cookbook nor a schematic of this design.
Any help appreciated!!
thanks! |
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Tim Servo
Joined: Jul 16, 2006 Posts: 924 Location: Silicon Valley
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Posted: Thu Dec 02, 2010 11:34 am Post subject:
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Hey Kupfer,
I'm working to get the VCO Chip Cookbook available for sale. It's a big chore, as I'm preparing a PDF from paper originals. Lots of scanning and cleaning.
I hope to have this available soon, but in the meanwhile I think some of the PCB layouts should be available. Right?
Tim (even have my wife helping scan stuff) Servo |
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