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para
Joined: Oct 16, 2006
Posts: 276
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 Posted: Sun Apr 08, 2007 2:10 am Post subject:
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would it be possible to use a LF394 backwards? thats all i have on hand. i do have a pair of 8038's though. if you can believe this i just did a whole stripboard for this, it was nice and compact but as i was saving the final changes my software crashed. the file will only load 32% now so i have to reinstall the program and start over, it keeps crashing. so annoying. i always save multiple copies of stuff but i was in a hurry.
thank you Mr. Henry for posting this. if you don't mine i'd like to post the stripboard layout here (not anywhere else) to save others some time. this will be my 3rd type of osc of yours. i guess owe a lot to you.
how did the power scheme come about? i’ve never seen anything like that, +15v doesn’t directly touch anything but the TL072. |
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iorobyy
Joined: Sep 26, 2005
Posts: 65
Location: Italy
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| Posted: Sun Apr 08, 2007 7:32 am Post subject:
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lm394 is NPN pair not a PNP pair , nothing to do!
You need something like 2sa798 (i think this would be ok)
NTE43 or similar as 2sa1349 (not common emitters).
However 2x 2n3906 (selected&matched) will works good.
Thomas is the king of this obsolete function generators.
Some time ago he make also some good schematic using the ne566...i've build various vco with this chips in thomas's unusual supply configuration ....simple but amazing!!
Could be a start point for a diy complex vco - based on fm synthesis (as dx7) using the triangle outs from various 566vco unities in various configurations (as dx7).
Uhmmmm...  ....someone could be interested to try to develope this idea?! |
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para
Joined: Oct 16, 2006
Posts: 276
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| Posted: Sun Apr 08, 2007 8:31 am Post subject:
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| but can't i use the lm394 backwards so it is PNP? |
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Scott Stites
Janitor
Joined: Dec 23, 2005
Posts: 4127
Location: Mount Hope, KS USA
Audio files: 96
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para
Joined: Oct 16, 2006
Posts: 276
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| Posted: Sun Apr 08, 2007 9:57 am Post subject:
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that's a shame. i tried searching for the 2SA798 but i couldn't find any. thanks for the link. i guess while i wait for those i can try matching some 2n3904's.
steven |
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iorobyy
Joined: Sep 26, 2005
Posts: 65
Location: Italy
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| Posted: Sun Apr 08, 2007 1:35 pm Post subject:
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Pnp transistor is builded in a different way from a npn.
Also responses and functions are different , not simply "inverted"!
So you need...2 discrete 2n3906 (not 3904! npn again!) matched or a PNP trans. pair as 798 that is a low price common emitter.
Ok also ssm2220! |
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para
Joined: Oct 16, 2006
Posts: 276
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| Posted: Mon Apr 09, 2007 3:04 am Post subject:
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sorry i was typing without referencing the part i.d's
i swear i've read that people have used npn's and inverted them and used them as pnp's (and visa versa) in order to get a lower noise floor in preamps and line amps. so i just assumed i could do the same thing here. it was a guy that designed some of the first multitrack tape console electronics, but i forget the name. i'm bad with names |
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Mikmo
Joined: Dec 01, 2005
Posts: 150
Location: Copenhagen - Denmark
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| Posted: Mon Apr 09, 2007 6:36 am Post subject:
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Could someone here confirm that the 2SA798 is a substitute for the lm394 ? Could it be used in Mr. Henry's XR VCO in stead of the LM394 ?
Thanks
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fluxmonkey
Joined: Jun 24, 2005
Posts: 708
Location: cleve
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| Posted: Mon Apr 09, 2007 6:41 am Post subject:
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this thread resurfacing inspired me to go back and finish up the quad linear VCO i started a few months ago, based on the 8038.
the switches next to the freq. control are range switches, regular or LFO. 2 CV ins per osc.; CV2 for osc 1 & 2, and 3 & 4, are normaled to the tri outputs of each other, so you have easy access to 2 pairs of cross-modulated oscillators.
from the descriptions, this might be similar to the core circuits of the 2 Livewire modulators (dalek and vulcan), but I have no idea if they are in fact similar.
finished it up around 9 last night and fooled around with it for another couple hours... much fun.
bbob
fluxmonkey
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para
Joined: Oct 16, 2006
Posts: 276
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| Posted: Mon Apr 09, 2007 8:10 am Post subject:
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no mikmo i had it wrong, sorry about that. the 2SA798 is PNP and the LM394 is NPN. the LM394 works in the XR and the 2SA798 works in the 8038.
steven |
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Thomas Henry
Joined: Mar 25, 2007
Posts: 298
Location: Southern Minnesota
Audio files: 2
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| Posted: Mon Apr 09, 2007 10:16 am Post subject:
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| bbob wrote: | this thread resurfacing inspired me to go back and finish up the quad linear VCO i started a few months ago, based on the 8038.
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Nice looking boards in that project!
Viewers might be interested to know that that kit was a pirate affair. The chap from Australia who put this out never asked permission from me, and obviously I never granted it. I suggested he might get more pleasure from marketing his own designs instead, but then he only accused me of being unreasonable.
For what it's worth, that was the straw that broke the camel's back and why I decided to go underground and cancel the Web site from which he swiped this circuit. Why should I design circuits for other people to make money from and I don't get a cent?
I don't think that unreasonable, do you? |
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fluxmonkey
Joined: Jun 24, 2005
Posts: 708
Location: cleve
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| Posted: Mon Apr 09, 2007 11:40 am Post subject:
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| Thomas Henry wrote: | | Viewers might be interested to know that that kit was a pirate affair.? |
Tom,
Obviously I was unaware that these PCBs were pirated. I am no lawyer, and would not pretend to know the ins and outs of copyright protection for circuit designs... but i would be glad to pay some kind of royalty charge direct to you to help compensate you for your work.
The loss of the information on your site was a real blow to the SDIY community, and my personal appologies if I inadvertently played any small part in it.
bbob drake |
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Thomas Henry
Joined: Mar 25, 2007
Posts: 298
Location: Southern Minnesota
Audio files: 2
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| Posted: Mon Apr 09, 2007 5:06 pm Post subject:
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No problem. It's not your fault that guy ripped me off. I was always rather proud of that design and wanted to do something with it myself. But like I say, I lost the ardor for electronic music when he told me I was being unreasonable by complaining about what he did. I don't need that sort of aggravation.
But enough of that, let's get back to the 8038. By all means, try another PNP matched pair and see what you get. And PNP's are indeed constructed differently than NPN's.
One possible mod: try an LF442 for the op-amps. I think they are more stable than the TL072 in expo converters. You can probably reduce the feedback cap at the same time, perhaps to 100pF. Make sure your layout is clean around that area.
About the negative supply: I did this to turn the response around. It works for both linear and expo VCO's with this chip. |
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WidgetOz
Joined: Sep 12, 2006
Posts: 4
Location: Sydney, Australia
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| Posted: Sun Apr 22, 2007 7:57 pm Post subject:
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Just for the records. I did email several times for approval but never got a response. I then posted the pcb but never claimed it to be my own design and actually replicated much of Thomas's original text as is and gave Thomas due ownership on the design.
As no pcb was ever made available I could not see any reasaon for designing and releasing a board for what was a good design and different approach to use of the chip.
When Thomas contacted me I followed up with a request for `official' permission to release the pcb but again never got a response.
I DO release my own designs but also like to support the community by making available designs that have long gone or never been made available in the first place. If the community believe this is piracy then I apologise - again I have NEVER claimed this to be my design and have always given Thomas credit for it...... |
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Thomas Henry
Joined: Mar 25, 2007
Posts: 298
Location: Southern Minnesota
Audio files: 2
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| Posted: Sun Apr 22, 2007 10:28 pm Post subject:
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| WidgetOz wrote: | Just for the records. I did email several times for approval but never got a response.
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If I write Stephen King requesting permission to reprint one of his novels and he doesn't respond, am I to take it that permission has been granted?
For the record, I never received any emails, but that isn't important. I don't doubt that they may have been sent, but they never arrived in my in-box. Regardless, the failure of email transmission for whatever reason does not automatically grant permission to make an income off of someone else's work. The only reasonable way to secure permission is by means of a written contract, sent via regular mail, which is in fact how I have handled my some 120 articles and kits over the past 25 years.
| WidgetOz wrote: |
I then posted the pcb but never claimed it to be my own design and actually replicated much of Thomas's original text as is and gave Thomas due ownership on the design.
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I can't believe this. I don't care who's name is affixed to the words, the fact remains they belong to me and no one else. "Due ownership" means nothing at all if I have no say in how or where my words will appear on the Web. And that's what really blew me away when I eventually saw this posted on a Web site verbatim. I can't even begin to understand a person who thinks they're doing me an honor by "replicating" my original text.
| WidgetOz wrote: |
As no pcb was ever made available I could not see any reasaon for designing and releasing a board for what was a good design and different approach to use of the chip.
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There is a reason even if it can't be seen: the design, the schematic and especially the words that were copied verbatim (including the warning about not copying the material---which was reprinted, too) are mine. Whether I decide to release a kit some day or not is nobody else's business. (And in fact I had intended to, but this whole episode has soured me considerbly).
| WidgetOz wrote: |
I DO release my own designs but also like to support the community by making available designs that have long gone or never been made available in the first place. If the community believe this is piracy then I apologise - again I have NEVER claimed this to be my design and have always given Thomas credit for it...... |
It's great to support the community. How about supporting the designers and writers who actually do the work? As mentioned above, it is irrelevent whether the person "NEVER" claims credit for my design or not; what is relevent is that it belongs to me and I have the final say over where, when and how it will be released. Anyway, it should occur to any reasonable person that freelance designers don't pay their bills with "credit" but by royalty payments.
I can't believe I just wasted a half-hour responding to something that seems so obvious: reproducing someone else's work without written permission---with their name attached or otherwise---is flat out wrong. Why should someone else reap the rewards of my many hours designing, testing and writing?
I was prepared to forget this episode, until the message above rolled in. In my 25 years of synth design and writing, and 10 years of Midwest Analog Products, I only once before had someone try to pull a stunt like this. I realize this is an aberration, but really, I am soured unless we all play by the rules.
I apologise to those of you who have always acted ethically in the past. But I am very angry after this. It's no fun explaining the bleeding obvious.
Thomas Henry |
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mosc
Site Admin
Joined: Jan 31, 2003
Posts: 18249
Location: Durham, NC
Audio files: 226
G2 patch files: 60
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| Posted: Mon Apr 30, 2007 9:48 am Post subject:
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[editorial]
This is a painful thread to read. My first reaction it to stay out of it, but I feel I have something to say. I hope something good can come out of this. I have been on both sides of this; I've stolen other peoples' designs and had mine stolen. Although I've never stolen music, I have had mine used by other people for commercial purposes (believe it or not).
Anyway, Thomas is absolutely right, to use someone else's work you must have their permission. You can't assume it's OK, or deduce it, or figure that since they didn't tell you no, or did not respond to a request, that they must agree. Nor can one assume that since they took down their web site or don't commercialize it themselves, that it is free for others to use. This goes for all intellectual property, circuits, music, etc. If we all understood this, then we'd all be better off.
The internet makes it easy to borrow stuff, but it doesn't justify it. Publishing the name of the designer is well intentioned, but it doesn't justify using the design without explicit permission. This is, I hope, clearly expressed on the electro-music.com conditions of use statement. It is common sense and, in most countries, it is the law.
So, I understand why Thomas would feel burned.
On the other hand, after reading WidgetOz's response, I don't think he is the Mother of All Evil. Certainly I'm not asking Thomas to do this, but I'm willing to give him the benefit of the doubt and assume he acting in good faith and was not intending to steal the design. I think it was a well-intentioned blunder. Hopefully this will come as a painful lesson to him, and a lesson to others, including those that take music and reprocess it or remix it without permission. Looking over the Elby site, I see that Thomas's designs aren't available there any more, a good start, IMHO.
If I was Elby, I'd send Thomas a PM and apologize and offer to pay him a reasonable royalty. Knowing the DIY synth business, I don't think Elby is rolling in cash flow from selling the VCO kit, but you never know. Likewise a public apology here in this public forum to Thomas would probably be appreciated by all. I'm not saying Thomas has to accept any of this, but I think it would be appropriate.
I think people like Elby who sell component kits and PCBs of DIY projects do a valuable service. In a small business, reputation is even more important than in a big one.
The rest of us can consider this incident carefully and learn from it. That is the good that can come of it.
I and many others hope Thomas Henry isn't so bummed by this and similar experiences that he reduces participation in the electro-music and DIY communities. We all experience some degree of fear and discomfort sharing our ideas and our artistic work on a public forum. That's why it is so important for us to express our appreciation to others when they do. We can never have too many posts that just say, thanks.
[/editorial]
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elektro80
Site Admin
Joined: Mar 25, 2003
Posts: 21959
Location: Norway
Audio files: 14
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| Posted: Mon Apr 30, 2007 10:02 am Post subject:
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Perhaps there really is a market for Thomas Henry branded kits and modules? 
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Coriolis
Joined: Apr 11, 2005
Posts: 616
Location: Stilling, Denmark
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| Posted: Tue May 01, 2007 12:55 am Post subject:
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I certainly would like to buy stuff from Elby in the future, especially if such an apology was given (and if it could make Thomas Henry approved kits available).
C |
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blanham
Joined: Jul 13, 2010
Posts: 2
Location: Chicago
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| Posted: Tue Jul 13, 2010 2:43 am Post subject:
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| I hate to drag an old thread back from the dead, but does anyone have the schematics that thomas posted on the first page of this thread? I came across a small cache of 8038's and would like to put them to good use. |
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magman
Joined: Feb 04, 2009
Posts: 363
Location: Liverpool, UK
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| Posted: Tue Jul 13, 2010 4:19 am Post subject:
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If nothing else, you can have a look at the AS21C "Super LFO" board here:
http://electro-music.com/forum/topic-29492.html
This uses an 8038 and ready made PCB's are available from Magic Smoke at a reasonable price.
I'm part way through building one, just need to sort out the front panel.
Regards
Magman |
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Thomas_Henry
Joined: Jul 24, 2009
Posts: 170
Location: N. Mankato, MN
Audio files: 3
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| Posted: Tue Jul 13, 2010 4:47 pm Post subject:
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Hi,
I checked to see if I still had copies of the schems mentioned. (They were apparently lost in a crash here on EM). Unfortunately, I don't. I'm pretty sure that it was the circuit which appeared in my VCO Chip Cookbook. At one time Magic Smoke had planned to republish it but I'm not sure they're still around.
You might check with Scott Stites to see if he saved copies. He has a tendency to hoard everything which, I surmise, makes him quite popular in a certain Mount Hope neighborhood. Heck, I bet he saved the defunct garage door opener...
Thomas Henry |
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PickNick
Joined: Oct 16, 2009
Posts: 82
Location: BP
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Scott Stites
Janitor
Joined: Dec 23, 2005
Posts: 4127
Location: Mount Hope, KS USA
Audio files: 96
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| Posted: Tue Jul 13, 2010 8:46 pm Post subject:
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Ahhrr....if I still have it, it will be several layers below the garage door opener (which I'm saving - I think it can be salvaged and converted to a workable mechanical pot). Haven't been able to turn up the schematics yet.
Cheerios,
Scott
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Tim Servo
Joined: Jul 16, 2006
Posts: 924
Location: Silicon Valley
Audio files: 11
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| Posted: Tue Jul 13, 2010 9:51 pm Post subject:
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Hi Everybody,
Yes, we're still around (Magic Smoke, that is)! I've been pretty quiet lately because I've been up to my neck in work, teaching classes, and helping around the house (my wife threw her back out and was off her feet for quite a while).
Anyway, I have Thomas' schemo for a linear response 8038 circuit on another computer. I'll grab that and post it here tonight. I'm also still cranking on the VCO Chip Cookbook and Thomas' new DVD. Things are finally settling down for me, so I going to be bringing some stuff out in the next week or so. Oh, and yes, we still sell the PCB for the 8038-based VCLFO from Thomas' AS21C book. 
Tim (not absent, just absent-minded) Servo |
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Tim Servo
Joined: Jul 16, 2006
Posts: 924
Location: Silicon Valley
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