Ah ok great, nice to know it’s working as it should!
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Yes, I haven’t measured how much exactly it works, but my ears and the Arduino detect no change. This is with the change to R13 to 200K.
EDIT: oh, and I also put a 1M between pins 4 and 5, so that could be contributing to the stability as well.
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I built mine, it works but has some problems. That’s the square wave with pulse width in maximum, that’s kind narrow still. (The ringing is from my mixer and/or audio interface, oscilloscope didn’t show it).
And bigger problem, the output signals frequency is very unstable, not in a way that it would drift, but like there’s very fast vibrato of 10 Hz to each direction going on. The frequency and width of it seem not to be dependant on the frequency of the signal, so it’s much more pronounced on the higher notes. What could cause that?
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OK this may seem like a simple/stupid question but 2 years on and I have a lot to learn.
1/v octave input… should that allow the keyvoard to pla a range of Octaves , does the octave switch just act as transpose?
My previous testing gave ( from memory ) limited range, but I may not have been too focused on the idead.
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Yes it should. The octave switch transposes from zero to four octaves.
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Well this is a pain Turns out my AKAI MAX49 CV and Gate outputs appear to be dead , unless it requires a mains and usb feed. BSP worked though.
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Well, the problem seems to be my power supply, it has 50 mV ripple on the positive voltage and 100 mV on the negative. This is more than enough to have effect on the oscillator. And now to debug what wrong with the power supply, it’s diy-kit of Frequency Central Routemaster. When I first built it, it had short on the negative rail to ground, and it fried that regulator, which I then replaced. Maybe something else suffered too.
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both the 1222 vco and 1112 filter come up as 404 when linking from KMG and are not listed on the store page
I think the filter’s discontinued, but the VCO? That can’t be right!
“SOLD OUT” items are currently not listed in the shop. probably a cms setting. it is safer to link to the respective project page.
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Hello,
So I have been playing around with tuning and calibrating my VCO but got a few issues.
Firstly. When people build these did they use a d shaft pot for the -6 +6 tune pot? I did not and so lining up exactly what the middle point is via the knob is really hard and causing tuning issues.
I was wondering about turning the knob all the way to the left and then adjusting the CNTR trim pot to make that C but then when I send 1v/oct info from my micro freak the notes don’t align. ie the c i hit on the microfreak to use to tune the VCO is right but if I press the C an octave below on the microfreak it is reading a D or even F#. I am thinking this is something to do with the arduino code?
Any thoughts on the best way to approach this?
Maybe I am just missing something super obvious
Sounds to me like your VCO doesn’t have 1 V/oct response and you need to adjust its scaling.
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Adjust scaling so full counter clockwise is G and full clockwise is G an octave above, then the center will be exactly C if you got it right. I wouldn’t worry about the arrow pointing exactly in the middle
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ok cool, is the scaling one of the trimmer pots?
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ah yes ok great, will give that a go as well, cheers dude
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The TRK (tracking) one.
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Hahah oh yeah!! Forgot that was an there!!
What does the cntr control technically do?
Just moves where the center is without affecting tracking.
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I have a quick start guide for the Eurorack version, but everything applies to Kosmo as well. It describes all the functions including trimmers. Any comments welcome:
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Looks great, very helpful dude
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