Here's how I used to calibrate the Dixie sines. I would hook up each Dixie to my PC-based Picoscope set to frequency spectrum mode. I would set the Dixie frequency to about 500 Hz, and adjust the picoscope software so that I could clearly see three or four overtones. Then, I would adjust the two trimmers until the second and third overtones were at a minimum. One trimmer caused one overtone to change, and the other trimmer caused the second to change. I did them in a specific order, and I can't remember that now. Using this method, according to the software, I could always get 1% THD or better, and occasionally (because of the luck of particularly well matched components) I could get THD down to about 0.3%. Those Dixies had bloody good sines.
Here's how to do it on your own. Listen to your Dixie through headphones or monitors in a quiet place. If you can look at the sine on a scope, this is good, but not essential. One trimmer adjusts the symmetry of the sine, and the other adjusts the shape of the sine. (The shape can go from square to triangle.) Listen carefully to the sine and try to identify the overtones. If the sine is "close" to well-calibrated, you should only hear the second, and maybe a bit of the third. Now adjust the trimmers to make them disappear. You probably won't be able to make them disappear completely, but you will be able to minimize them. That's really all there is to it.
Einen "unbehandelten" Rubicon gibt es ja nicht wirklich, die trimmen den Sinus auch händisch. Gibt da auf jeden Fall Schwankungen zwischen den Modulen.
![[dunkel]](/synthesizer/data/avatars/m/4/4106.jpg?1504014001){kind=avatar}
