Hell yeah! I love crazy ring mod sounds, this looks like a nice easy build. Great job!
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Dual VCA, half can be omitted for a single VCA.
“verified” via reddit: https://www.reddit.com/r/synthdiy/comments/mz1tyn/chaotic_stripboard_layout_for_a_dual_vca_based_on/ (Should verified by people outside of our forum be in the other thread? That thread seems more for I-made-this-but-haven’t-tested-it-yet)
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Interesting circuita, but the sockets are connected to -12V, is that correct, shouldn’t they be connected to ground?
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Yes good check ! 
the jack socket must be connected to GND not -12V
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I built the design and connected the sockets to ground, unfortunately it doesn’t work, checked everything, too bad!
It’s also misnamed — this isn’t a ring modulator.
The 100k at the top also should connect to ground, not -12V. (Sorry, my misinterpretation.) The 100 nF cap from -12V to ground isn’t needed, I would think, since -12V is unused by the chip. In principle the other cap should be closer to the IC but that probably doesn’t matter much, and I’d put a 10 µF cap from +12V to ground near the power connector.
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Yeah, thats true. Sorry my mistake, I will update it.
The bypass caps, I put these on all of my builds. The 100k resistor IT HAS TO BE CONNECTED TO -12V. Check the video mate.
You post a bad layout, schematics that don’t match the build (*), and now you’re yelling at people who comment on what you posted. Maybe drop the attitude?
*) or maybe they do match, but Kristian’s schematics are a bit different from the ones you posted.
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I know you put the 100 nF bypass caps in your build. I can see your photo. What I’m saying is one isn’t needed, the other could be closer to the chip, and it would be good practice to include 10 µF as well.
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Im not yelling at people, Im trying to help them. And If somebody has a problem with the layout I will update it asap, because I know that there are way more skilled people on this forum. And if you want me to do something with layout, tell me and I will update it.
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Okay, thanks for the advice. I will do that in my future design.
In the version above, it looks to me like the output (with a 100k load) would swing between about -500 mV and +550 mV. The 4.7k to ground brings the amplitude way down. Without it you’d get about ±4 V. But either way the output impedance of 47k is very large.
By contrast, in the version @fredrik points to, the output impedance is a much more reasonable 1k, but the voltage swing is about 0 V to 11.5 V. Neither the 47k to ground nor the 100k to -12 V does much of anything because the output resistor is so much smaller.
I would think you’d want about ±5 V and 1k. With a 1k output resistor, a 2k to -12 V, and no resistor to ground, you’d get ±4 V.
Neither of these schematics makes much sense to me.
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Can you use AC coupling here? Capacitor + resistor
I’d think so, but given this is the “verified stripboard layouts” topic, maybe it shouldn’t be posted here until you’ve tested it. I’ve been known to come up with wrong ideas.
And yes, I’d think you could use AC coupling instead. Or an op amp level shifter.
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I also built this 4011 ring mod (following Kristan’s initially flawed schematics). It seems very finicky about when it chooses to do the “Ring Mod” thing. but then I also crammed it onto the very smallest piece of stripboard I could and I rushed it (was done within about 2 hours of his video premiere complete w/ front panel and I had a 1 hour staff meeting in there.)
I like the sound of the 1496P ring mod more… although the issue with that one is it also needs input attenuators.
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Well, the LM1496 is an actual balanced modulator chip. You can debate whether anything that doesn’t have four diodes in a ring should be called a ring modulator, but at least it’s doing basically the same thing, multiplying two analog signals. The above circuit isn’t; it’s doing logic on digital signals, or what it expects to be digital signals. What it’ll do with anything other than pulse wave inputs is hard to tell. One could stick comparators on the inputs and that might get it to behave better… or worse… who knows.
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Just a casual reminder that this thread is for stripboard layouts that have been verified to work, not ones that still need to be verified and troubleshot.
Feel free to open new threads to discuss, we just want to keep this thread more tidy for people just showing up here to grab some designs.
There isnt a strict measure for what “verified” means, but i would venture that one should at least have built this first without any noticeable issues first. I would also assume that by posting here, you assume the responsibility to help people with any issues as best to your ability.
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Yeah, totally. I will create a new topic. Thanks!
I will take down the unverified layout and post it here:
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