After watching a few tutorials I’m starting to get an understanding how the FM synthesis has been designed on the Digitone, but I keep wondering why Elektron have chose to call the second pair of operators B1 and B2 and not B and D?
Most 4-Operator FM synths have them numbered 1 to 4 or A - D. What is different about the Digitone that means they are labelled B1 or B2 or do they just behave the same as other FM synths regardless of these labels?
Never had that question, always was intuitive for me because they are mostly controlled with one encoder. Their settings are coupled.
Having numbers 1 and 2 is important because of the order in which they are affected.
1 always changes first.
2 - either changes after 1 goes through a cycle or after you reach middle of Levels.
from the manual:
We have divided the operators into three groups: C, A, and B (B1 and B2) to lessen the complexity and make the Digitone easier to use. Since group B consist of two operators, the parameter controls for B are macro mapped to both operators.
so it’s three groups with the B group having two operators…
edit: btw, the manual has a very good section on fm in general, worth a read. also, i really like watching the wave forms, so i hook up DN to live and run it through a scope to see the morph of the wave, i have occularScope (free vst) but there are probably other ones…
Thanks, makes a bit more sense now 
There is also a good reason to call them B1 and B2 instead of B and D, it’s the fact that they share the same modulation enveloppe (the B enveloppe).
sweet. thanks for the tip!