Joined: Apr 17, 2006 Posts: 2812 Location: New York
Audio files: 25
Posted: Mon Jul 02, 2018 8:35 am Post subject:
Thanks for the reply. Going to save this schematic and this information. The CV can always be scaled in other applications. Would be good to get my hands on the 561LN2 to hear a difference. For now the 4069 will suffice.
What is the Drum envelope generator you're using???
This one:
J-chot wrote:
oh man, how does that resonance even work?
Are you mean the second filter?
I do not really understand why, but when you block resonance with parallel cap. in long fedback line, it's starting to resonate when you change coefficient of summing amp.
I created a PCB and built up your "screams wilder" Russian 4069 circuit this weekend. Used a Russian 4069UB. sounds GREAT maybe a cross between a MS20 filter with peak cranked up and a synthacon, but gnarlier!
Keep up the good work! _________________ Visit my AUDIODIWHY blog and website
And here is the newer newer version. Almost linear resonance and a loads of it. Self oscillation and so on. This version works better with CD4069 unbuffered. Low pass bypass and hipass also available.
Tested on breadboard with digital potentiometers.
4069_LPF_RAVEN_L.mp3
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4069_LPF_RAVEN_B.mp3
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4069_LPF_RAVEN_RIFF.mp3
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4069-4.jpg
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To change cutoff with CV use digital 100K pots and an arduino right?
Not exactly. I do not use CV, Arduino have simple decay envelope function and analog pot. to control decay. It's only gate signal here.
Digital 100k pots connected in series with analog 100k pots to have manual control of cutoff. Low end of one digital pot is connected to the 1/2 Vcc, it works like VCA.
I haven't decided yet, do I need fully functional ADSR, CV, or just single pot, like Korg Monotron have. Single pot also can have slow and fast attack angles.
You can hear some hiss sounds, but this is because it's builded on breadboard and use USB power right from PC without any capacitors.
Thanks to Hammer for help with this project and post! He's continually updating and I may fab a Eurorack version down the road. _________________ Visit my AUDIODIWHY blog and website
Hello Hammer and all of you
reviving this thread after 1.5 years with a question as I have started to test your filter.
when I check for Russian CMOS chip equivalents I find no 4069.
and К561ЛН2 is supposed to be a 4049 according to this page http://zpostbox.ru/ussr_analogs_of_cmos_ic.html
is this correct? not a problem anyway but important to consider regarding the pinout
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Now I think that any another unbuffered CMOS hex inverter with high frequency of operation (> 2 Mhz) will be better than too old but cool К561ЛН2. Maybe 4049.
Hello! Greetings from Argentina. While searching for variable filter circuits, I ended up here. I designed a PCB based on the schematics I found in this forum and added an output for the high-pass filter.
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maybe a cross between a MS20 filter with peak cranked up and a synthacon, but gnarlier!
