By the way, I was wondering and thinking if this was a particularity of the "0Hz carrier FM", that is: a FM patch with no carrier frequency. But I tried other regular FM patches with a carrier signal and could see that it didn't keep static as well.

On the other hand, the same patch implemented as Phase Modulation (PM) maintains a static waveform in Pd.

In my last example, the patch I had as "waveshaping" could be thought of as a "0hz PM" patch.

Now, I tested the PM stability with the [phasor~] + [cos~] architecture and also with [cycle~]. 

The FM instability happened with both [osc~] and [cycle~].

In Max, a FM patch with [cycle~] is stable.

In short, there's something fishy with FM in Pd...

cheers

2015-11-21 13:25 GMT-02:00 Alexandre Torres Porres <porres@gmail.com>:
> Can you elaborate?

Not easily I'm afraid, so I'll try to keep it simple: it's a demonstration on the relationship between FM and waveshaping, compare now both patches in my new example. The waveshaping does not change through time.

But let me attempt to reason why it should keep static - it's like any other FM patch, once you have set the parameters, the waveform must be static and not change in time. My tests with supercollider and Max had a good result (waveform kept static). I also tried in Pd with cycle~ and in the newest vanilla.

cheers

2015-11-21 11:26 GMT-02:00 Roman Haefeli <reduzent@gmail.com>:
On Sat, 2015-11-21 at 02:59 -0200, Alexandre Torres Porres wrote:
> howdy, attached there's a patch where I was experimenting with FM
>
>
> the waveform shouldn't change with time, but it does. Give it a while
> though, 30 seconds is enough to hear a change in tone quality, then
> resseting the oscillator phase brings it back to where it was
>
>
> don't know why it does come out of phase, an equivalent patch in SC
> and Max does not get out of phase...

I hear and see what you mean. Interesting question. Frankly, I don't
quite understand why it is expected to stay in phase. Can you elaborate?

Roman


_______________________________________________
Pd-list@lists.iem.at mailing list
UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list