Re: [chuck-users] phase modulation and hard sync?

3 Jun 2017

      2017-06-03 15:01 GMT-03:00 Jean Menezes da Rocha :
...
Unfortunately, my knowledge of SuperCollider is very limited and I don't
feel like I'm able to translate your code.
Here's an attempt to make SC code clearer.

Here's the fm example I found in chuck, using sync = 2

////////////////////////////////////////////////////

SinOsc m => SinOsc c => dac; // modulator to carrier

400 => c.freq; // carrier frequency

201 => m.freq; // modulator frequency

1500 => m.gain; // modulation index

2 => c.sync; // FM synthesis (sync is 2)

while( true ) 1::second => now; // time-loop

////////////////////////////////////////////////////

And now for the SC equivalent

////////////////////////////////////////////////////

{var carrier = 400; // carrier frequency

var modulator = 201; // modulator frequency

var index = 1500; // modulation index

var m = SinOsc.ar(modulator) * index; // modulating signal

var c = SinOsc.ar(carrier + m); // frequency modulation (carrier +
modulating signal)

Out.ar (0, c ! 2)}.play

////////////////////////////////////////////////////

and now a phase modulation example in SC

////////////////////////////////////////////////////

{var carrier = 400; // carrier frequency

var modulator = 201; // modulator frequency

var index = 2pi; // modulation index

var m = SinOsc.ar(modulator) * index; // modulating signal

var c = SinOsc.ar(carrier, m); // frequency modulation (carrier +
modulating signal)

Out.ar (0, c ! 2)}.play

////////////////////////////////////////////////////

note, the SinOsc in SuperCollider takes frequency input as the first
variable in parenthesis, and phase (in radians) in the second.

cheers

2017-06-03 15:31 GMT-03:00 Alexandre Torres Porres :
...
2017-06-03 15:01 GMT-03:00 Jean Menezes da Rocha 
...
:
...
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