My build progress


Years back, I told my nephew who is really into space that I lived on IO (Jupiter’s moon, that IO). For years its been a fun back and forth. He sent me a video saying he doesnt think I live there anymore.

I knew these blinky lights would prove useful in my hijinks one day.


I have finished the wiring and testing of the 8 Step Sequencer. I used Eddy Bergman’s circuit diagram. Features individual step CV control, step speed control and number of steps. Enjoy.

Eddy Bergman’s page : Eddy Synthesizer Build part-8: 8 STEP SEQUENCER.


My girlfriend painted a frontplate for me. Thick watercolour-paper glued onto a aluminum plate with lacquer on top seems good enough. I don’t actually mind if things get worn or scratched, it just shows that they are used and loved. When buying used gear, especially guitars, I don’t trust if the instrument shows no marks of usage. It’s probably not a very good instrument if it hasn’t been used much.


Elsassisch isch bombisch :slight_smile:

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I have the 8 channel filter working (only needed six here). I think it sounds awesome, resonance is quite picky though. It can be tamed by the trimpots but when you are on the edges it produces some pretty funky sounds. Cutoff frequency is also controlled by LFO and/or ADSR.

I fixed some problems on the MIDI implementation of the DCO, also USB MIDI seems to work now. There has been an update of the Raspberry Pi Pico SDK and it now uses upstream copy of TinyUSB.

I think I got a proper polysynth now! Okay, it’s quite basic and I’m still missing some casing but it works.


that front plate is beautiful . I love the artistic face plates like this and Sam’s too .

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Started two builds today - one is Erica Synths Basslines, which will take a while to finish up as I buy components, and the other is Mutable Instruments Ripples. It’s my first SMD build and honestly don’t know how it’s going. Very hard for me to tell if it’s passable or not - will find out when I power it up I guess!


Ahah of course ! The best french region !! Power of bretzel !!

mon arrière-grand-mère venait d’Alsace et je vis à 80 km au nord de Strasbourg.


Pas très loin de chez moi alors… à 20km de Sarrebruck…


@eric @TrapaNatans

Purée les gars excellent le monde est petit, c’est ouf! Jetzt getz los !! Quand vous voulez pour une petite session picon-son !! :slight_smile:


Hey buddies,

just a little fast & dirty patch for test my new quad LFO module

The module idea come from here:


Woah, this is great! Awesome jam!

I like a) that YouTube channel and b) that little circuit!

I think I’ve mentioned this before, but suppose I wanted to build a little 5cm Kosmocto (Ochd – the second DivKid Eurorack module! in Kosmo format) - could I add a direct (or attenuated) CV input then an attenuator on that +12v volt line, then feed it to all different LFO circuits to add the CV to give the whole thing a master control knob?


Thank sista !

This is a really good idea but I don’t know if it is possible, you must to try it ! :slight_smile:
Please keep us informed of your discoveries and progress !
The octo project look very interessing !

Later I want to build a voltage controled LFO too with a speed cv input and some more controls for better precision.

Now I integrated a VCA into my case !

I have good working today so it’s time to go in bed yet !

Have a good day !!


Good sound !
You’re building at lightning speed :slight_smile:

it makes me really happy to hear the modules ringing.
It’s an instrument, so to make sounds, music
With the number of people & modules built on this forum, I am always amazed at how few sound are posted since the creation of the forum.


Ahah thank ! :facepunch: Yes I activated my most faster internal clock to speed up my construction in order to can begin to playing music ! :slight_smile:
because I’m first a musician before to be an engeneer… Hihi

Next jam I will be record with a soundcard for have better sound !
Im discovering patching joys and I make a lot of noodle nodes ! :stuck_out_tongue:
I have a lot of modules builds in 9v one year ago who I go to adapt for ±12v dual voltage

Synth in progress, going to become alive !


Not sure I follow. You want master CV control of what? Frequencies or amplitudes? If the latter you need a VCA on each output, with CV going to each. If the former you need a more complex LFO circuit. Or for cheap and dirty CV a vactrol on each LFO probably in parallel with the frequency pot, with op amp LED driver; might or might not give you the kind of results you want.

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Well, maybe building an instrument is easier than playing it, or people are too modest to post their music?


The advantage with the modular is that you can have fun right away by turning the knobs, whereas if you learn an instrument like the piano, the fiddle, the guitar … it will take a certain amount of time before be able to have fun with the instrument.
It was just a thought, even without talking about “conventional music”, doing bleep bloop and other buzzz :slight_smile:
But indeed some surely prefer to build than to play with and i really hope nobody hesitates to post some sounds here.