zynthia - sequencer synthesizer

using a 40106, 4051 and a 4029 to make some noise, following the Logic Noise series on the blog

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using a 40106, 4051 and a 4029 to make some noise, following the Logic Noise series on the blog by Elliot Williams and other projects I found here.

There will be an updated video of it soon, when the parts are all here and the 4028 is in, but since the log with the first video won't show here anymore, I've embedded it here.

Here's the update!

sch - 541.38 kB - 07/13/2017 at 21:48


brd - 108.06 kB - 07/13/2017 at 21:48


sch - 343.41 kB - 07/11/2017 at 21:45


brd - 97.65 kB - 07/11/2017 at 21:45


  • 1 × CD40106 - hex inverter Logic ICs / Gates and Inverters
  • 1 × CD4029B - binary counter Logic ICs / Counters
  • 1 × CD4051B - multiplexing IC Switches and Multiplexers / Analog Switches and Multiplexers
  • 1 × CD4028B - Binary to decimal decoder Logic ICs / Decoders, Encoders, Multiplexers, Demultiplexers
  • 10 × Potentiometer 100k Ohm b/log

View all 12 components

  • More Zynthias being build

    davedarko09/16/2017 at 16:45 0 comments
  • Rev2 boards are here

    davedarko08/10/2017 at 20:26 0 comments

    I still have to update the OSHpark Board, there are some minor label changes (if it works at all, that is :D ):

    C2 is a 10nF cap

    C1 is a10uF cap

    So this board should have all the bells and whistles it can:

    • 8 LEDs
    • 8 Tone knobs for pitch
    • up/ down switch for the counter
    • binary / decimal switch for the counter (count to 8 / 10)
    • Synced oscillator switchable
    • Speed for the counter potentiometer
    • Sync / Pitch knob

  • Gaaaaah ... it was too close to midnight!

    davedarko07/13/2017 at 21:33 0 comments

    Thanks to @al1 I'm now aware that I've mixed up the GND and VCC symbols from the schematics of @Elliot Williams :D So now it's corrected and everything looks even cleaner! Definitely will sleep on ordering this one (hopefully al1 will have another look, just to be sure) :D I'm not looking forward to the boards arrival - straight to the totem of failure, I guess.

  • smd version

    davedarko07/11/2017 at 21:42 0 comments

    I came around to design an SMD version of the perfboard version :)

    On board is:

    - 8ch LED port

    - 8ch potentiometer port

    - counting up/down switch

    - octade (binary) / decade switch

    - synced pitch switch and potentiometer

    - speed potentiometer

  • a little upgrade

    davedarko02/04/2017 at 23:23 1 comment

    I've bought one of those cheap LM386 DIY kits on eBay and upgraded Zynthia to be fully stand alone. I only had 10 red caps for the resistors, so I took green instead and a dymo label, the last switch is now the power switch :) I also mixed up one power cable and without checking I've almost killed a battery by shorting it :D

  • 4028 - installed

    davedarko04/26/2015 at 19:03 0 comments

    Same colors for knob and led cables. Yay. Not sure what it is this time, but the BCD mode gets funky when it's going down. Anyway - I haven't posted a pic from the inside for a while.

    I can't find a mouse to edit a video in blender on a mac, so the ring modulator video has to wait a bit... but here's a video of the working 4028. And yes, my calculator recorded this! (well no, you got me, it id not)

    Found the mouse, it's rendering!

  • 4011 - ring modulator

    davedarko04/24/2015 at 21:25 2 comments


    2015-04-27 video added

    I totally like this stuff more and more! I found a ring modulator circuit built with a single 4011 over here:

    I plan to add a frequency divider / D- flipflop made out of a second 4011 to auto sync the modulator, with no clue how it will sound or if it will work.

    Makes me want to buy an oscilloscope.

    Here's the D-flip-flop in NAND gates turned to a T-flip-flop, which I didn't use because reasons - taking the 4017 instead.

    Thanks to @haydn jones for sharing his #Open 4,4 Sequencer

  • hardware vs. frequency

    davedarko04/23/2015 at 13:57 2 comments

    I've made a table to see the frequency range of the potentiometers vs. capacitors in 10 steps and categorized them to see what values make sense for what spectrum/range.

  • painted the box

    davedarko04/21/2015 at 20:25 0 comments

    I was in the mood for some spray paint fumes and since I wanted some LEDs I had to add some holes and the golden print was drilled through etc. so I made the box metallic blue - that's also the color of my guitar, my FX pedal and my loop station - so it will fit right in some day ;) I had no dymo labels in black left, so I took the red ones. Heavy contrast and all, but with the "oil paint" weathering makes it look really really great. Only the up/down and bcd/dec switches are missing and I will have to make the DC and output plugs going somewhere. I drilled a hole for the DC plug and almost ripped the box apart but was able to glue it back together. Here's a "not weathered" picture:

  • You get what you've paid for

    davedarko04/21/2015 at 18:50 0 comments

    It's not that important, but when I noticed that one tone pot was off in the lowest position I decided to measure the 100K potentiometers I've bought for 2,10 Euros. Here are the values:


    Look at these percents! I've ordered some more to get equal values. But I guess that was what to expect :D

View all 16 project logs

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Morning.Star wrote 07/12/2017 at 06:28 point

Bibbity-bibbity-bibbity @ 2:12 made me howl with laughter dude.

Howcome I never saw this before, its awesome! :-D

  Are you sure? yes | no

davedarko wrote 07/12/2017 at 08:22 point

hm, maybe because it's older and I haven't done stuff on it for a while? I wanted to revisit this after MakerFaire, it was a fun attraction :)

  Are you sure? yes | no

oshpark wrote 07/12/2017 at 01:12 point


  Are you sure? yes | no

Adam Vadala-Roth wrote 07/11/2017 at 22:09 point

I can dig it, music and electronics go well together, skulled and following

  Are you sure? yes | no

esot.eric wrote 04/13/2015 at 00:30 point

I dig the 4000-series audio tutorials, too. I haven't yet gotten around to building one, though. It boggles my mind that so much analog-esque audio stuff can be done with a few CMOS (logic) chips. 

(IIRC My hacker-number was 40106 when I signed up... I recognized it was a cool thing to have a CMOS hacker-number, but never knew all this stuff could be done with it!)

  Are you sure? yes | no

davedarko wrote 04/13/2015 at 00:53 point

I might use the 40106 with a digital potentiometer on my R8-D8 project, but I also wanted something "CMOS only". I will try something different with the boards - print a sticker for the top and print out a mirrored version as a guide to solder the wires to the perfboard. And then I hopefully have something noisy/analog/logic synthesizer -ish :)  

so why is it 40107 now? Have you sold 40106 to Muhammad from Indonesia? ;)

  Are you sure? yes | no

esot.eric wrote 04/13/2015 at 01:02 point

dag-nabbit, 40107, you're right... (How did you find that out? I couldn't figure out where that info's stored anymore). Guess he's the lucky one.

Ahh, perfboard without copper? Interesting sticker-idea, I look forward to seeing it. (You've seen those little plastic DIP labels they use for wire-wrapping, right?)

  Are you sure? yes | no

davedarko wrote 04/13/2015 at 01:20 point

Hovering over your user name told me this - "My hacker-number was 40106 when I signed up" - sounded like it changed, so I checked what it is now - but it wasn't my intention to check/control you because I did not believe you :) 

Is perfboard without copper? Hmm. I meant the single sided copper boards that are pre drilled. Proto(type)board then? Those labels seem to be very useful, but I can't use them or something similar :( But I hope a mirrored printed sheet helps not losing track while soldering this board.

  Are you sure? yes | no

davedarko wrote 04/13/2015 at 01:21 point

holy moly - it's 3:20 am o.O off to the batbed, batman.

  Are you sure? yes | no

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