Phase Distortion Synthesis

[Ingonator]

To avoid some confusion:
FM = Frequency modulation
PM = Phase modulation
PD = Phase distortion
AM = Amplitude modulation

Yes. But beware: many developers (and not only amateurs) make themselves these confusions (voluntarily or not, I don't know and it probably depends of these developers)

There is some confusion but usally between FM (frequency modulation) and PM (phase modulation). Even Yamaha did that...

Phase distortion seems to work differently and usually you need dedicated PD oscillators for it.

Nemesis seems to be a good synth for comparisons as with the same basic settings and waveforms you could switch between different synthesis methods like FM ("NeoFM" modes), phase modulation ("FM/PM" modes) and Phase distortion ("PD" modes).
Also depending on the wavefoms used for the Carrier and Modulator all 3 do sound differently.
FM and PM could sound similar with very simple waveforms like a Sine or simple "sinoid" waveforms.


Ingo

[justin3am]

Nemesis seems to be a good synth for comparisons as with the same basic settings and waveforms you could switch between different synthesis methods like FM ("NeoFM" modes), phase modulation ("FM/PM" modes) and Phase distortion ("PD" modes).

Bazille is also great for these kinds of comparisons. Not only can you apply Phase Modulation, Phase Distortion and Exponential Frequency Modulation to each oscillator at the same time, but you can change the Phase modulation mode to use Thru-Zero Linear Frequency Modulation (a feature rarely, if ever, seen outside of analog modular synths).

To access the thru-zero modes in Bazille, set the Phase Mode (which defaults to PM Coarse) to Lin 100hz/1khz for addition of the modulation signal to the carrier's frequency. Set the phase mode to Rel Fine/Coarse for multiplication of the modulation to the carrier's frequency.

[Ingonator]

Just did 3 audio demos with Tone2 Nemeis using one oscillator with the same parameters but with 3 different synthesis modes (PD, NeoFM, PM):

1.) Phase distortion (PD):
Nemesis - PD Pad 01

2.) FM (NeoFM):
Nemesis - NeoFM Pad 01

3.) Phase modulation (PM):
Nemesis - PM Pad 01

The phase modulation is similar to that used in the famous DX synths (as already mentioned those did not use "real" FM). The original DX7 did only include Sine waveforms where FM and PM do sound quite similar.


Here is a screenshot with the waveforms and oscillator parameters used (only synth method changed ; PD shown at the screenshot):


In all 3 cases the "Neo FM" knob controls the amount of PD, FM or PM.
For FM a lower amount would lead to a more "pleasing" sound maybe. Very high FM amounts are usually not the best choice in that case.


Ingo

[xh3rv]

There is some confusion but usally between FM (frequency modulation) and PM (phase modulation). Even Yamaha did that...

Phase distortion seems to work differently and usually you need dedicated PD oscillators

PM and PD share the technique of having a waveform mapped into digital memory such that memory addresses equate to phase. Simply by turning sample values into memory addresses, signals can modulate phase. Without any modulation an oscillator in either is basically a ramp wave signal into the memory map.

While PM adds signals from other oscillators to this 'phasor' ramp wave, PD just distorts the ramp. There's more to the CZ-style implementation of PD but that's the basic technique.

[PaulSC]

For the "multi-synthesis synths" that I know or that I have heard about, here are some which have PD with absolute certitude:
[snip]
ElectraX

I'm pretty sure ElectraX (and likewise the forthcoming Electra2) emulates PD by scanning through a wavetable. Which is fine but maybe shouldn't qualify it for inclusion on the "PD with absolute certitude" list…

[xh3rv]

I'm pretty sure ElectraX (and likewise the forthcoming Electra2) emulates PD by scanning through a wavetable. Which is fine but maybe shouldn't qualify it for inclusion on the "PD with absolute certitude" list…

IMHO if it's distorting a phasor it's probably fair enough, although that's not necessarily equivalent or sufficient to emulate CZ sounds. Due in part to history and patents and marketing, one could claim CZ stuff is The One True PD, but not on just the technical points.

[drunken jesus]

Thanks for the great info from many people on this subject

Of all the synths that have been mentioned only one I can recall using is Kickmaker & I'd highly recommend it, cool little drumsynth great for making kicks/basses and random weird pecussion noises I managed to get some great 808 style kicks and some c64 style drums (using a bit crusher) from it pretty easily.

Going to give Digits a try next time I work on a project. It's demo sold me on it's sound plus it comes with a decent number of presets. It's interface looks amateur friendly as well lot of the others had pretty crazy looking interfaces that I imagine would take a good bit of time to figure out.

Really wish freeware & some payware(is this a word lol) would take the time to put up a simple sound demo and list how many presets a synth comes packaged with it'd really benefit their exposure/sales imo, besides Digits none of freeware synths had a demo song & only Mothman listed the number of presets, all the payware had sound demos (except plasticz it had a broken soundcloud thing embedded) but only Phasewave listed the number of presets

Oh and to others that may be interested Phasewave offers a free monophonic version with 64 presets & no limitations, very generous offer of them

[BlackWinny]

Going to give Digits a try next time I work on a project. It's demo sold me on it's sound plus it comes with a decent number of presets. It's interface looks amateur friendly as well lot of the others had pretty crazy looking interfaces that I imagine would take a good bit of time to figure out.

And I've just seen that it has a compilation for Linux. Rare enough to be applaused!

except plasticz it had a broken soundcloud thing embedded

You can listen to it here:
https://soundcloud.com/search?q=plasticz

[Ingonator]

After i stsrted checking phase distortion in Nemesis i am currently testing it in the public Beta of U-He Bazille.

While in Bazile there seem to be more options to shape the sound the advantage of Nemeis seems to be that you could use custom waveforms (Bazille includes the "usual" PD wavefoms).
Anyway both have their own approach and it could be great to have both.

The intro price of Bazille seems to be quite tempting but i need further testing to decide if i really need it.


Ingo

[BlackWinny]

On the same page than Kassiopeia (here) I discover that the same developer has made another Phase Distortion synth in his collection of "Sinthecyza" synths. It is the number 2.6. (Last Updated 05/07/2005) I didn't know it and propably you neither... A new one to experiment!


Oh! And below still in the same page, the number 4.2 (Last Updated 03/09/2006)

[BlackWinny]

Anyway both have their own approach and it could be great to have both.

Yes. I'm highly in agree with you. Almost everywhere I see kind of quarrels "This one is better than that one!" "You stupid! That one is far better, trust me!" and it continues on page and pages...

And very often, in fact , each of these two synths has its qualities. And I'm pretty sure that absolutely all the synths have their qualities and can be "the best" for someone and "the worst" for someone else.

The pity is that generally things are not discussed on their real features and on objective data but only on personal subjective judgements.

[fmr]

Most FM synths including the Yamaha ones did not actually use FM but phase modulation which could be similar but depending on the waveforms used also quite different. Tone2 nemesis with the "NeoFM" synthesis modes offers "real" FM while it also includes a few phase modulation ("PM") modes. The difference of real FM could be noticed when using complex waveforms which do not really work properly with phase modulation.
Ingo

Although technically PM is no FM, when using only sine waves, which was the way it was done by it's "inventor" John Chowning, it's virtually the same thing. Actually, when I questioned John Chowning about this we was pretty much emphatic when he said: "Yamaha synths ARE FM as I created it". The only difference is that Chowning (and Risset) many times used much more than six "operators" when creating his sounds in the Music N family programs. That's why, when I asked him if he would ever thought of using a hardware synth, he told me that he once tried (together with David Bristow) program his sounds in a hardware synth, but he needed the TX816 (which means eight DX7s).

The conclusion is: you don't need (and probably should not use) complex waves, but rather a bigger amount of sine waves.

[Ingonator]

Most FM synths including the Yamaha ones did not actually use FM but phase modulation which could be similar but depending on the waveforms used also quite different. Tone2 nemesis with the "NeoFM" synthesis modes offers "real" FM while it also includes a few phase modulation ("PM") modes. The difference of real FM could be noticed when using complex waveforms which do not really work properly with phase modulation.
Ingo

Although technically PM is no FM, when using only sine waves, which was the way it was done by it's "inventor" John Chowning, it's virtually the same thing. Actually, when I questioned John Chowning about this we was pretty much emphatic when he said: "Yamaha synths ARE FM as I created it". The only difference is that Chowning (and Risset) many times used much more than six "operators" when creating his sounds in the Music N family programs. That's why, when I asked him if he would ever thought of using a hardware synth, he told me that he once tried (together with David Bristow) program his sounds in a hardware synth, but he needed the TX816 (which means eight DX7s).

The conclusion is: you don't need (and probably should not use) complex waves, but rather a bigger amount of sine waves.

The Neo FM mode in Nemesis seems to work nicely with complex waveforms (and Sine is indeed quite similar...). Like shown in my demos at this page using the same waveform in the FM (Neo FM) and PM modes (similar to those in the DX synths) could sound quite different.
With the waveform additive editor of Nemesis (when used from scratch) you could more or less use a bunch of Sine waves at the same time. In the "Classic FM" soundset this was used in combination with the phase modulation modes. The next upcoming soundset will focus on the NeoFM, Formant and Reso modes.

Anyway as mentioned above i am currently checking the phase distortion in both Nemesis and Bazille (and also in a few free Reaktor ensembles).


Ingo

[Numanoid]

Anybody tried NeoGen? It only 32 bits (SE), but tempting at sale now only €25

[dakkra]

Mutools MUX has a phase distortion "transform" in it's MFO. It's actually rather nice

Little Demo:

https://soundcloud.com/dakkra/mutools-m ... st/s-kjvvr