2017-06-03 15:01 GMT-03:00 Jean Menezes da Rocha <jean@menezesdarocha.info>:
Alexandre,

As far as I understand it, the .sync attribute is more like an identifier, rather than a true numeric value (that is, 0 says you are syncing frequency with frequency; 1 says that you are syncing phase with frequency; 2 says you are doing true Frequency Modulation). As you are telling that no value means no sound, one can infer that there is no default value for that, and if you are feeding UGen => UGen, telling which is your sync method is mandatory (but I can be mistaken, as usual).
 
there may be a default parameter, right? And that seems to be 0. If I have sync at "0", I hear no sound.

Anyway, it doesn't seem like the sync parameter is able to do hard sync. It seemed that the "0" value would do that, but, as I said, I hear nothing.

If phase input is linear in chuck, then the code from SuperCollider would be equivalent, but it is not. And even if it wasn't linear, I tried it with radian values and did not get the same results.

I suspect it is not really doing phase modulation because it doesn't matter if I change the carrier frequency, and that is weird.

well, I guess I'm repeating myself, sorry, just anxious in the hope of clarification.

thanks