Blog

new synth module?

By: FreyaPublished: 25/05/23 13:01:59

yo

damn its really been 6 months since i last posted huh? oops. ive been busy since i moved & its been really hard to find time & energy to post on here.. but i will do it cos without cohost this is the only place i can really post long-form style about my synth modules and buddy u better believe i made a new1 one

my logic module (& a normal quantity of resistor legs) my logic module again but from the side so u can see my attempt at managing the panel wiring more cleanly,

this ones a logic module. originally i was gonna just make a quick module with a few inverters on it so i could use my baby8 sequencer properly, since it turns out its gate input triggers on the falling edge of the clock signal for some reason? instead of the high edge like all my own modules do. which meant that it was always half a beat out of sync and sounded weird. and not the good kind of weird like u want from a modular synth. bad weird.

as always it got totally out of hand almost immediately and what i ended up with was a full set of logic gates on this damn guy. from top to bottom, it's got:

  • and
  • nand
  • or
  • nor
  • xor
  • xnor
  • not
  • not (again)

i think part of how i ended up going for more than just not gates was that it felt like a waste to not use the rest of the inverters on the 40106 chip i was gonna use, so i went digging for info on making other types of gate and found this page on mfos about mml logic2. most of the logic circuits are slight adaptations of the ones there, but the xor/xnor gate was based on a diagram i saw3 of how to build an xor out of nand gates, and i just kinda made it out of the mml nand circuits. which means i had to add a second 40106 just to do that and also it still leaves me with an unused inverter! but it lets me do cool & weird rhythms by shoving multiple clock signals into it..... so maybe its ok.

other than that the only major difference from the mfos circuit designs is that im using +5v for the pull up resistors and i added a few transistors to cap input voltages at +5v, all so that i can give it higher voltages (eg. audio signals) as input. i thought i could get away with just feeding whatever voltage into the 40106 and that as long as it was running off 5v it'd just cap it there, but instead it turns out that above 5v the input just goes straight thru and out of the chip's output even when the chip itself is unpowered!! its scary!!!

i think thats about it for what i got to say about this module. i've updated the synth page so u can click that to see it installed, or u can find it on my eurorack schematics repo if u wanna see how it fits together. hopefully i'll find more time to post about other stuff i've been up to soon4..... for now tho i return to figuring out what the fuck an ota is so i can build a vcf module,

– freya


  1. i actually finished it like a month ago. ive been busy. gimme a break....

  2. at time of writing this is actually down, which is concerning. i've linked it anyway cos i'm trusting whoever owns the website now will have it back up soon but just in case u can find it on archive here

  3. and now can't find. where did it go !

  4. ive been up to so much stuff dude i was not joking about being busy