Speaking of Theremins, one of the items on my “toys I want” list:
Best I can recall - glissando - the gliding from one note to another. Depending on how the filter is set up - freq over/under shoot of the target freq. Also a divider (digital) can be placed in loop causing the output to be a multiple of the input. Need to dig through my archives for the notes. I tinkered w/ basic ckt w/ CD4046. Interesting part.
I can see how that might work. I think I’ve seen kits for 4046 VCOs too.
As noted above, I plan to use the modern copies of the 3340 that Moog used. Thanks to Behringer, they’re back in production.
Looks like 4046 has a lot of uses / is a workhorse VCO with sample and hold functions… another chip to explore… thanks!
I like this approach, sounds like a good start.
http://www.milkcrate.com.au/_other/sea-moss/
has good explanations of using only three chips CD40106(6 stage Hex Inverter), CD4040(a binary counter / divider.) and CD4051 (8 channel analog multiplexer) to generate tones.
Some info on the CEM3340 / AS3340:
I’m looking at it because it has so many good things built in. Temperature compensation, proper scaling, 3 waveforms.
https://electricdruid.net/cem3340-vco-voltage-controlled-oscillator-designs/
There are top octave generators (ICs / modules). Decide what you want for the top octave and divide by 2 for the rest. Don’t think the 4046 would make a good solo vco - typically used as an “effects processor”. Apparently the different brands/makes of the 4046 are not consistent in how they respond to cv.
Darcy Neal, synth artist/designer and former member of DMS, sent me this interesting link on the topic:
https://www.birthofasynth.com/Thomas_Henry/Pages/X-4046.html
Motorola datasheet:
https://www.uni-kl.de/elektronik-lager/418071
RCA CMOS Databook pdf - go to pg 494
http://bitsavers.trailing-edge.com/components/rca/_dataBooks/1986_RCA_High_Speed_CMOS.pdf
And yet another trip down memory lane.
One the 70’s electronic hobby mags had articles on synth ckts. Think it was Popular Electronics.
May still have copies - buried deep in the archives…
Might be able to find at archive.org or bitsavers.org.
The Thomas Henry site Art linked is a good one.
A Eurorack version of this is what I plan to build:
https://www.birthofasynth.com/Thomas_Henry/Pages/VCO_Maximus-Detail.html
( The posted design is +/- 15 V. Eurorack is +/- 12 )
VCO Maximus Eurorack kit:
Is the CEM3340 chip used in a lot of vintage synths? Cause your link has a lot of classic synths including a “SH-101” circuit that looks approachable… Do you have the chip/built anything with it so far?
It was used in some of the early Moog synths and a lot of others. It makes it relatively easy to handle a lot of common problems synth designers run into. Temperature compensation and sync most notable among them.
It went out of production for a while and the old stock prices for the chips made it up to $40-50 each.
Then in recent years Behringer wanted a source for the new synths they are making, so they partnered with a chip fab and you can now get modern versions ( pin and function compatible ) for $4-5 each.
My Behringer Neutrons each have 2 3340 VCOs.
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BTW, if you want the simple version of a 3340 VCO, take a look here.
https://www.lookmumnocomputer.com/cem-3340-diy-simple
You can get single chips from US shippers under $10 on eBay.
The source I plan to use is in Poland. $41 ( IIRC ) for 10.
Engadget: Korg launches a line of DIY music gear with a $100 synth.
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My son has a couple of these and they are amazing for the money. (except for listening to drum loops at 3am).
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Greetings everyone, my name is Jaret Kojac and I’ve recently joined DMS. One of my agendas here is to help develop the Digital Media dept.
I have over 25years in Audio Engineering, Synthesis and Sound Design experience and have also worked as an educator in the above fields. I’ve also worked with a long list of companies in audio hardware and software.
Part of what I’d like to develop for the curriculum for this department is a set of Audiotronics classes.
It seems the interest is here, so let’s talk. Please feel free to talk to me as soon as possible about what you’d like to see and how you would be interested in contributing.
Thanks!
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I have an arcade game sound board here with 6x CEM-3394 chips on it. Would be fun to make something cool with those chips.
I am interested in learning what I can from you. Have you spoken to @Kevin yet? He is really great at helping people get started in the Digital Media department at DMS.
Yes, Kevin and I have been speaking and working together when it’s possible. I have a busy schedule, as does Kevin… whom is doing wonders for not just this dept. but many; however, I have a lot of faith and vision for this multidisciplinary dept. just as Kevin does.
Being new to DMS, I have to admit that it is a bit difficult to learn and navigate all of the procedures and politics necessary, but I tend to believe that if an effort is made and people collaborate on a shared vision, that it can become what it capable of.
That being said, I’ve stated I’m entirely approachable and I’d like to make things happen. It’s also upon all of us to help make them happen.
Please feel free to contact me directly if there’s any way anyone feels they can contribute.
Great to have you here. Sorry for the late response, but totally interested in your background. What did you have in mind when you wanted to develop a curriculum? Have you made any headway? Looking forward to connecting with you
I might be interested in those chips.
I have an old Akai AX60 DCO//DCF/DCA synth that may need new SEM chips and I’m looking to restore it.