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lostinpurdy
Joined: Nov 16, 2007 Posts: 37 Location: Gig Harbor
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Posted: Sun Oct 25, 2009 5:43 pm Post subject:
4049 hex inverter Subject description: vco/vca/vcf applications - looking for examples |
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Hello - it's been awhile since I posted anything and I was just beginning to understand the concept of (music) electronics but then things happened and I had to abandon it all and eventually lost interest.. until now. So after messing around with some beginner circuit I came across the 4049 which is basically 6 inverters in a chip. Now knowing that inverters are commonly used especially in vco and lfo circuits, I was wondering if this chip would be a good candidate for such applications or even vcf and vca applications? Are there any examples flying around out there? I'm kind of aiming to build a single chip based synth.
Greetings, Patrick |
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lostinpurdy
Joined: Nov 16, 2007 Posts: 37 Location: Gig Harbor
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Posted: Sun Oct 25, 2009 6:13 pm Post subject:
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just noticed I posted that into the wrong place.. |
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blue hell
Site Admin
Joined: Apr 03, 2004 Posts: 24079 Location: The Netherlands, Enschede
Audio files: 278
G2 patch files: 320
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Posted: Mon Oct 26, 2009 2:14 pm Post subject:
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lostinpurdy wrote: | just noticed I posted that into the wrong place.. |
ok, moved it up a bit. _________________ Jan
also .. could someone please turn down the thermostat a bit.
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Dave Kendall
Joined: May 26, 2007 Posts: 421 Location: England
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DGTom
Joined: Dec 08, 2008 Posts: 211 Location: Adelaide
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Posted: Tue Oct 27, 2009 5:59 am Post subject:
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Grab the datasheet & take a look at the pin out of the 4049 to see how really wierd that cct. is,
4049 / 4050 don't follow standard CMOS VCC / VSS |
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Dave Kendall
Joined: May 26, 2007 Posts: 421 Location: England
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Posted: Tue Oct 27, 2009 7:25 am Post subject:
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WOAH!
pin 1 is VCC and pin 8 is GND?
Blimey - that is seriously weird......
cheers,
Dave _________________ "Everything in moderation, including moderation" |
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lostinpurdy
Joined: Nov 16, 2007 Posts: 37 Location: Gig Harbor
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Posted: Tue Oct 27, 2009 9:14 am Post subject:
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hm.. so judging from the schematic it'd give me about 6 vca's in one little circuit? would it be possible to substitute the opamp with one of the internal inverters as a buffer so that I (hopefully) get a single chip vca, vco/lfo/AR, vcf design out of it? I'm thinking of using two inverters to be switchable between astable and monostable mode so that either of them can be used as a vco, lfo or attack/release generator, one inverter for vca, one as a simple vcf, leaving the remaining two as buffers for vca/vcf. Just an idea for a one chip synth/module I'm hoping to put together. |
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JovianPyx
Joined: Nov 20, 2007 Posts: 1988 Location: West Red Spot, Jupiter
Audio files: 224
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Posted: Tue Oct 27, 2009 10:26 am Post subject:
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Don't forget to look at 4069UB and 4007. These ICs are interesting for synthesis as well.
The difference between 4069UB and 4049 is that the 4069UB has symmetrical output transistors and the 4049 does not.
The 4007 is almost a transistor array and often, individual transistors can be used. 4069UB and 4007 can be used to make VCF, VCA and VCO as well. _________________ FPGA, dsPIC and Fatman Synth Stuff
Time flies like a banana. Fruit flies when you're having fun. BTW, Do these genes make my ass look fat? corruptio optimi pessima
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DGTom
Joined: Dec 08, 2008 Posts: 211 Location: Adelaide
Audio files: 3
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Posted: Tue Oct 27, 2009 3:38 pm Post subject:
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:facepalm: should have mentioned the 4069, ScottG has some FANTASTIC ccts. using that little critter It feels really wierd saying (typing) it but... its a great sounding CMOS chip
I think Mark Verbos even posted a message to the SDIY list awhile ago mentioning he subbed it into an old Buchla waveshaping cct. with good results! As well as a few VC Fuzz type things I've also built a fairly resonable low pass gate with it, still tinkering with the CV input of that however - responds great to big rail to rail pulses from other CMOS but not so well to envelopes or more usual CV sources.
Somehow I still havn't got around to trying Rene S. 4069 VCO |
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jnuaury
Joined: Feb 28, 2008 Posts: 161 Location: chicago
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Posted: Tue Oct 27, 2009 11:43 pm Post subject:
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wow, that 4049 circuit is really intriguing, looks "passive" too
any info on what EFM this is from or any more information on the circuit? |
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stolenfat
Joined: Apr 17, 2008 Posts: 476 Location: Sunny Oakland California
Audio files: 1
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Dave Kendall
Joined: May 26, 2007 Posts: 421 Location: England
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Posted: Wed Oct 28, 2009 4:41 am Post subject:
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: jnuaury :
EFM was a site started in the late 90s by Tom Gamble. Lots of circuits were published, and many of them made into circuit boards for sale.
They were inexpensive, and a great way for someone *less* than very rich to get into building synths
Tom no longer sells PCBs, but does have some VST plugins on his site. http://www.ele4music.com
CJ Miller kindly sent me that schemo from a collection he had made from early posted stuff while there was a forum on the EFM site. I doubt if there are any notes still existing about that particular schematic, as the EFM site and forum died and were born again a couple of times, and a lot of the early notes were lost.
The most complete collection of stuff I've seen on the web is hosted by Fonik here
http://www.modular.fonik.de/Page37.html
cheers,
Dave _________________ "Everything in moderation, including moderation" |
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lostinpurdy
Joined: Nov 16, 2007 Posts: 37 Location: Gig Harbor
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Posted: Fri Nov 06, 2009 9:37 pm Post subject:
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thanks for all your input - the LFO looks promising and I'm pretty sure it could be turned into a VCO and EG kind of thing - as a matter of fact I might try to accomplish a multifunction modulation device out of that, which ideally would be swithable between VCO, LFO and EG modes. Now what would be the likelyhood of using the 4049 for VCF applications? I've seen simple lowpass and bandpass VCF circuits using an inverting op-amp topology and since inverters are basically inverting op-amps I should be able to make some decent VCF out of that, right?
PS: Why the 4049? Because that's what came with my Radioshack lab. And that's the only kind I have right now.. inverter wise that is. I ain't rich, ya know.. |
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yusynth
Joined: Nov 24, 2005 Posts: 1314 Location: France
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Posted: Sat Nov 07, 2009 1:50 am Post subject:
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Many years ago, Sam(Osamu) Hoshuyama did post on the SDY list a series of designs of his of a basic modular synth all based on CMOS circuits.
You can find it al here :
http://www5b.biglobe.ne.jp/~houshu/synth/index.html
Some of these brilliant designs:
_________________ Yves |
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The Real MC
Joined: Jun 20, 2008 Posts: 62 Location: Painted Post NY
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Posted: Tue Dec 15, 2009 1:17 pm Post subject:
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I've been looking into that EFM hex VCA circuit.
The 4049 is a hex inverter IC. Manufacturers build their inverter circuits differently and this schematic may very well be dependent on an inverter design from a certain manufacturer.
It may not even work with a 4069.
The problem is, the IC manufacturer is not specified in the schematic. Most tinkerers will be confused if they breadboard this circuit and it does not work.
Some of the clever circuit designers have been known to design a circuit around the substrate makeup of ICs. The old minimoog has one such circuit - the 741 - that will not work with modern opamps. |
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richardc64
Joined: Jun 01, 2006 Posts: 679 Location: NYC
Audio files: 26
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Posted: Tue Dec 15, 2009 4:33 pm Post subject:
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I don't care who has had what success with the things: I will never ever trust digital CMOS used linearly, except in the simplest of applications, e.g. no-frills amplifiers, as used in the Osamu Envelope Follower and Noise Generator circuits. (Do you hear me, all youse over there in the Lunetta forum?)
lostinpurdy wrote: | hm.. so judging from the schematic it'd give me about 6 vca's in one little circuit? would it be possible to substitute the opamp with one of the internal inverters as a buffer so that I (hopefully) get a single chip vca, vco/lfo/AR, vcf design out of it? |
Negative. Look at how the 4049 is wired. Vcc and Vss are connected together, creating an output "buss" of all the mosfets' drains and sources. Individual inverters are not available separately for any other use.
btw, I've looked at 4049 data sheets from National and Fairchild and the innards appear identical. The 4069 is slightly different, so, indeed, it may not work in the hex VCA circuit.
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_________________ Revenge is a dish best served with a fork... to the eye |
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
Audio files: 23
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Posted: Wed Dec 16, 2009 12:19 am Post subject:
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great diagram, richard! thank you. _________________
cheers,
matthias
____________
Big Boss at fonitronik
Tech Buddy at Random*Source |
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
Audio files: 23
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Posted: Sat Jan 26, 2019 12:50 pm Post subject:
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Ten years after! Wow.
Good things need time...
PRB617 wrote: | Thanks again. I did try the circuit again and it does work fine now. I'm not sure what I did wrong, I may have not had the VCC +5 to the best inverter connected the first time around and it might have back fed through, but it's good now. |
_________________
cheers,
matthias
____________
Big Boss at fonitronik
Tech Buddy at Random*Source |
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blue hell
Site Admin
Joined: Apr 03, 2004 Posts: 24079 Location: The Netherlands, Enschede
Audio files: 278
G2 patch files: 320
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Posted: Sat Jan 26, 2019 2:52 pm Post subject:
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Better to not reply to spam fonik ... edited some stuff out of here ... _________________ Jan
also .. could someone please turn down the thermostat a bit.
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
Audio files: 23
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Posted: Sun Jan 27, 2019 2:59 am Post subject:
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oopsie.
have not been aware of the situation. _________________
cheers,
matthias
____________
Big Boss at fonitronik
Tech Buddy at Random*Source |
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amarello
Joined: Feb 20, 2024 Posts: 1 Location: Colombia
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Posted: Mon Mar 04, 2024 7:06 pm Post subject:
I found it |
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Dave Kendall wrote: | Hi Patrick.
Maybe try the hex VCA schemo below - it's an old EFM design, and looks interesting.... Haven't tried it myself.
EDIT - I guess +V is on pin 16, and GND on pin 8 , but I'm not sure how pin 1 works, as it seems to be connected to GND as well as the input to the TL071.
Hmmmm.. Anyone seen anything like this before?
cheers,
Dave |
https://www.paia.com/talk/topic-481.html
Hello!
crazy circuit, i´m gonna test it
someone has seen this working? |
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