Hi guys,
Came across this one and it sounds awesome.
And this is the schematic
Im not seeing any opamps used for inputs and outputs. Is there some improvement needed?
Or is there someone here that has build such module from a better designed schematic?
Thx
Have a look at the Barton Waveshaper, it uses a 4046 with some buffering I/O around it.
Hi Jos
Thanks for your reply. Gonna check that out. Have a nice day
Ok, i just saw that Eddy Bergman has build this one too. Need to figure out what Phase Lock Loop (PLL) is and does. Is it part of a frequency multiplier? Or is it another module on its own. Time for learning i suppose.
Very briefly: a PLL is often used to stabilize a frequency. It compares the generated frequency to an input signal and corrects its output frequency if necessary. However, if you feed back a signal that has been e.g. divided by two it corrects for that value resulting in an output frequency twice the input frequency. Using various dividers you can thus choose your output frequency from the output of the PLL (not from the divider).
A PLL generatea an output waveform that has its frequency matched to that of an input signal (the “reference frequency”). To achieve this, it attempts to lock the phase of its internal VCO to that of the input signal using a comparator which compares the phase of the input signal to that of the reference VCO and sends the output of the comparator to a filter to smooth out voltage fluctuations, ensuring a steady phase relationship between input and output signals. The PLL uses, in turn, that smoothed out phase difference to adjust the phase of the VCO. This “phase lock” process works in a loop, where the signal of VCO is sent back to the phase comparator, completing the loop (hence, we have a “phase locked loop”).
The most utilized function of PLLs has been in frequency multiplication and synthesis where frequency counters or dividers are entered in the loop between the VCO and the phase comparator. By presenting some logic function between the VCO to the phase comparator it is possible to “trick” the phase comparator into locking to a frequency that is a multiple of the reference frequency, creating, therefore, a frequency multiple at the output of the VCO once the loop has been completed.
I have build it and does not work completely which means, it passes through a square wave from my vco with nice artifacts but as soon as i plug in C4 capacitor (socketed it for testing), i hear high pitched sound rendering complete silence. I’ve send a message to this guy and he said try changing this or that see if it leeds to better results, nah it does not. Switching sounds does work with nice artifacts but not as in his video. Never seen other similar schematics on the net including these 4 Cmos type IC’s
I hope maybe someone is willing to build this thing and try if its working. 
I give up. Its not worthed. If this is so hard to build and experimenting with it without damaging the ic’s there is where i draw my line. Breadboards, yeah well. That’s another point of discussion for the a litany of dumbassery topic. Either the components fall into the hole to loose, no making sufficient contact, and taking out the components, i need big ass pliers to jank them out. Thanks to Velleman. Their breadboards just suck.. viewing video’s of @moritzklein where he is inserting components, wires etc without any crackles in sound makes me angry hahaha. Like i said a post for another topic. For now im done with breadboards.
C4 is for the loop filter, it just affects the VCO responds to changes in the input signal. What’s the input signal like? The frequency of the VCO is affected by R1, R2 (which you have open), C2, the 4046 supply voltage, and the voltage seen by pin 9. Since you have no output voltage on pin 9, you need to see what’s coming in from pin 14 and how the loop filter gets it into pin 9. You should see a triangleish wave in pin 9 after the input has been squared by the internal self bias circuit and integrated by the loop filter. Maybe the VCO frequency is too high?
If you haven’t worked with 4046 before try to get this to work first on breadboard before building something more complicated. The 4046 is the most complicated CMOS with many different building blocks inside it (a VCO, two phase comparators and a few other things as well). Adding three more CMOS on top and going straight to stripboard leaves many possibilities to go wrong!
Hi,
Ok thanks for the info. Didnt know this. I was under the assumption that if i follow the schematic everything will just work out fine. No matter the complexity. Just like following a recipe when you try to cook something. Apperantly this one needs more trial and error on the breadboard to get the best results.
Thanks!
I took a couple of those small form breadboards (the cute and colourful ones sold in a pack). I added long IC sockets hot glued to the centre.
Why? CMOS shizzle be fussy as hell to prototype with. 
(Lunetta synths can kill with noise and frustration - I hear)
One thing I changed is that I use square ‘blade’ IC sockets, not round pin as the round pin sockets cause “flutter” when you push flat IC pins into a tube (a technical term for it’ll arse about - I’m sure).
On some breadboard mockups I have used my stash of wire ends, the bits you snipped off, to solder stronger legs onto potentiometers, transistors, those tiny caps that vanish when they touch a floor, so they work better with a breadboard.
Lastly good breadboards are worth the time and money, remember unless you’re making a huge prototype you’re bound to only need a couple.
Soldier on!
Hi Farabide
Thanks for your advice. The last 4 TH VCO555’s ive build straight from the schematic onto the PCB. No need to breadboard them. As long as the schematics are correct or workable i just printed them schemo’s out on A4 paper (210x297millimeters) and sharpie those lines when done.
Would you mind taking a look at this?
I have builded this on breadboard but not the results as in the video. I tested and tested and experimented, destroying 2 ic’s in the process (cd4040 and 4017 getting very hot) leaving me with a non working thing. In the video it sounds awesome, but im not able to replicate it even its a simple circuit. Do you see any parts that could be optimized? I have messaged this fellow and helped me out but i have my doubts if the schematic (start at video), is the same that he has build on the breadboard. I really would love to have a module that sounds just like that. I never came across such a module or schematic on the www. Its seems that Unrelated Activities has something special.
Thanks for your advice.
Schematics
My breadboard
Obviously i have replaced every ic on the board but with no success
Sure, I’ll take a proper look over the weekend and have a go myself if I’m able. I know I have all the components. Are you sure you’re using the same capacitors?
I’ll get back to you soon
Thanks a million.. really appreciate it.
Absolutely no rush. Im glad you look into it.
Regarding the caps. I have ceramic, mica, poly versions so should be no problem. Maybe you can use an opamp for input and output and extend its functionality by adding a gate input alongside the manual switch for changing sounds. Or maybe you can sqeez out more from this cd4046 chip. Im curious what you come up with
No bother. It’s been a while but I do remember I had to test various resistors on the inputs, though I’m buggered if I can remember why. It’ll be in the data sheet or my notes. I’ll sing when I’m winning.
Can you put this schematic into falstad simulation? And push its possibilities to the max? 4 cmos chips.
I notice you don’t have a DC blocking capacitor on the pin 4 output of the CD4046, just the resistor.
Also I see a capacitor on pin 8 (gnd of the CD4046) but I cant see what is connected to the other end. Is it being used to decouple or not?
Hi Craigyb
Thanks for joining in. To be honest, i dont know. The schematic isn’t mine, just trying to follow the schematic on the video which isnt hard at all. I’ve build way more complicated stuff and im able to troubleshoot some issues but i’m also limited.
I cannot verify if this schematic is correct. Fortunately another member of this forum is taking a shot at it. Thanks to @Farabide
Also looking how to squeeze more out of these 4 cmos IC’s. So im waiting curiously…
I’d be weary of unverified schematics found on youtube. I looked at the comments and others have problems replicating this. None of the ICs should get hot, so there’s definitely something wrong with it. You need to make sure that the signals flow from IC to IC. Check your input at the 4046 pin 14. What does it look like Vpp? Then check the output at VCO out right after the pin and at the output jack. You should have a square wave in both cases, although the shape at the jack will be messed up due to the filtering. I am not sure the capacitor makes sense at the output. I’d just put a voltage follower instead without AC coupling. Also check the outouts of 4040. You should also have triggers there. Also make sure all ICs are powered by the same supply and have 100nF bypass capacitors close to the supply pin.
Hello Farabide,
Hope you doing well.
Any luck with the CD4046, CD4017, CD4051 and CD4040 frequency multiplier thingy?
Thx
Hi there, I have all the parts assembled but have yet to test the build. I’m stuck abed at the moment. I do think that the issue may be related to the input signal but I’ll sing when I’m winning.
Hi,
Im confident that you will sing. If you could replicate it the way it sounds just like in the video would be great. Im sure you can do even better and make it better.
