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delay with pm modulator

Posted: Mon Feb 22, 2021 10:32 am
by AutumnCheney
hi, i noticed that with the modulator module, there is a delay when it is set to phase modulation

this is apparent when you stack a bunch of them on top of each other; i have linked an experimental metamodule that demonstrates this, the sound doesn't play until a few dozen miliseconds after you input a note

is there anything you can do about this?

Re: delay with pm modulator

Posted: Mon Feb 22, 2021 5:49 pm
by NightRadio
hi, i noticed that with the modulator module, there is a delay when it is set to phase modulation
Yes, that is right. But the algorithm works differently for the "phase" and "phase (absolute)" modulation types.
Phase modulation is simply a variable delay controlled by the amplitude of the modulating signal.

1) Modulation type = phase
Default signal delay = 20ms.
If the amplitude of the modulating signal = 1, then the delay length = 40ms
If the amplitude of the modulating signal = 0, then the delay length = 20ms
If the amplitude of the modulating signal = -1, then the delay length = 0ms
So the active delay range is the following:
40ms (amp 1) ... 20ms (amp 0) ... 0ms (amp -1)

2) Modulation type = phase (absolute)
Only absolute amplitude values will be used.
Default signal delay = 0
If the amplitude of the modulating signal = 1 or -1, then the delay length = 40ms
If the amplitude of the modulating signal = 0, then the delay length = 0ms
The active delay range is the following:
40ms (amp 1) ... 0 (amp 0) ... 40ms (amp -1)

So please try to use the mode (2).
It sounds a little different, but it has no latency by default.
Check my NR FM Drum.sunsynth from instruments/drums/FM/

Re: delay with pm modulator

Posted: Mon Feb 22, 2021 7:22 pm
by AutumnCheney
interesting, i didn't know it worked that way

thanks to you, i was able to fix the module! i just had to dc offset the modulators to remove the latency. now, there is an attack, but it only lasts a few hundred samples or so. it also fixes the issue of it sounding too different with different notes

i can release the module now!