I agree it is rather strange!
I’ve never found voltage regulators to need such exact conditions to function before. Perhaps there’s an error elsewhere that’s just on the border of causing the regulator to freak out, but it’s a high quality PCB soldered carefully, so I’m not sure what the issue could be.
At least it’s all working now - thanks again for your comments on this.
Haha, thanks very much!
The finger should pop out of a little door…
other than KOSMO - 5u is one of the most beautiful formats in my eyes.
I love Buchla, Serge, and such, but man, something about the black and silver 5u panels with the bends on the sides.
Gorgeous work.
I am planning a KOSMO panel for the FB with the help of @lookmumnocomputer when he remembers to send me something 
I looked at a few formats when I started in 2008 and the Moog / dotcom panels did seem the nicest. Big jack sockets and plenty of room around the knobs! I guess the scale of the interface seemed close to some analogue synths I had already so it seemed a natural choice.
Yeah I have the same issue powering it with 12V AC, I have to turn it on, then off while letting the voltage slightly drain, then quickly turning it on. I’ll look into that regulator, thanks!
The working and non-working regulators I used were both made by STMicroelectronics, only difference seemed to be that ‘3’ on the end.
Waiting for the post…
Question: does c14 have to be 1uF? Can it be smaller or can i use an electeolytic 1uF?
It’s the envelope capacitor. If you make it smaller, your envelopes will be shorter. The non-GND side will be exposed to both positive and negative voltages, so an electrolytic will probably not be too happy (it’s basically this circuit for which the instructions say “can be any ceramic/polystyrene whatever as long as it isn’t polarized”).
You could use a couple of 0.47uF caps in parallel, for instance.
Thanks for all your help! I just finished it. I used small plastic pots for attack and release because i don’t have the regular ones in 1M.
Can someone tell me how to calibrate this thing now?
The upper ones are 3340 scale trimmers (check the various 3340 threads for how to best trim them), the others shift the triangle output up and down, iirc. Sam explains how to trim them here:
in the modules i built with the 3340 there were 4 pots for trimming, so i am a little confused… and i could not find a good hint here in the forum.
Love the doooo00000oooodles!
Fart box: done
It is everything I hoped it would be. I am still a little mystified around tuning it. What did you all do, specifically, to “tune” it?
In the meantime, I’ll be reading the data sheets hoping for some insight.
Yeah, mine is nowhere near in tune 
Yeah I don’t even know if you can set it at 1volt/oct, though running something through does work at certain settings.
You made the Buchla Easel of Fart boxes. It’s beautiful.
