It was also the Sam’s vid about calibration 
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Cheers chief, I watched this a couple times but after doing so I knocked the tune nob and it went out of whack then wondered about an idiot proof fix where all the way one direction gets you locked into your note again
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Yeah, if that’s your jam, you can just adjust the CNTR trimmer until C is at the end of the range.
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I tried that but it then didn’t talk with my MIDI keyboard sending cv to it.
Didn’t line up
You should be able to just adjust the center trimmer until it does line up.
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Hi all,
I posted an optimized version of the code here : Kosmo / Tune-OO-Matic · GitLab
It works on a '168 Nano, which is nice with today’s high prices of a '328 Nano…
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This is, slightly modified (switched to a common cathode display and different renditions of some characters), what will go in the second batch of the Eurorack 1222.
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Anyone know if sockets for the Arduino Nano are available on Amazon? I ordered supplies to build 3 VCOs the other night, but forgot to grab the sockets!
I’m super new at this, and I’m not sure what exact socket I’m looking for unfortunately!
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I used a 32 pin wide dip ic socket for mine and removed end pair of pins as 30 pins sockets don’t seem common, I think that what Sam recommended on his build video too.
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Found some on ebay! Thanks for the reply, that was a huge help!
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I use a pair of 15 position pin sockets.
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I have done all of the above . clipped the ic dip sockets , used pin sockets , and used the sockets made for that application . all work just fine .
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Good afternoon!
I’ve just completed my first 1222 VCO and have run into a few issues. The first issue - my square wave is out of tune. I can tune the ramp and triangle to C across all octaves, but the square will still be out of tune. Any ideas?
Also, the fine tune knob does not go a whole octave up or down. I’m positive that I used a 100k pot, but I will definitely check again! Any help is appreciated!
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That… doesn’t make sense. The pulse wave is created from the triangle wave (as is the ramp). They all have the same frequency by definition.
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Adjust the TRK trimmer. Make sure you’ve gone through the whole calibration procedure.
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@analogoutput @ChristianBloch Thank both of you guys! I mistakenly had a 10k resistor in the R9 spot when it should have been a 47k. That fixed my issue with the pulse wave being out of tune.
I think I misunderstood the octave fine tune knob to begin with! If my module is tuned to C, the fine tune knob should bring it to G at complete rotation both up and down? I was thinking it would bring it back to C again.
This is the last issue I have thankfully! When I turn the octave switch to the highest setting, the display on the tuner goes crazy. I’ve included a short clip of what’s going on. Any ideas?
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Weird, I haven’t seen that resistor making much of a difference in that value range and Sam says the same. And it really shouldn’t affect the frequency especially since it’s always connected regardless of what output you’re using. Are you using AS3340 or CEM3340?
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AS3340
That was the only thing I swapped out and immediately saw a huge improvement. It was definitely off with the 10k!
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Something really weird then. I’ve definitely never seen that behavior with an AS3340.
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The tune knob is designed to be ± 1/2 octaves, so it appears you are working as intended 
Both of mine do the same.
Congratulations on completing the build
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