Do PW and Poly PWA work correct? I don't think so.

[LBH]

Do PW and Poly PWA work correct? I don't think so.

First:
1. The PW's give no sound when fully up. I realize why. But i suggest the value ends at 98 so there is sound when the knobs is fully turned right just like when it's fully turned left.

Then:
2. When using polymod and use the FILT ENV to control PWA, then i would believe the effect the value have on the PWA should be at least half of what it is at the time being.
EXAMPLE: If i on a sound only using OSC A PW and
set OSC A PW to the value ZERO/ fully left, and
set the FILTER ENV SUSTAIN to MAX/ fully right
then if i go over the value 38% on the POLY-MOD FILTER ENV there is no sound from there and up.
In this case i would say when the SUSTAIN in the FILTER ENV is at MAX then it should be like when the OSC A PW is at MAX, and when the SUSTAIN is ZERO, it should be like when the OSC A PW is at ZERO. The SUSTAIN should work like the OSC A PW does.

In the same example similar issues arrive, when for example using the ATTACK and the DECAY in the FILTER ENV instead of SUSTAIN.
If you for example set ATTACK and DECAY in the FILTER ENV to MAX/ fully right and have the POLY-MOD FILTER MOD at MAX too, then you get a massive hole in the sound in the middle (No sound). I would say that in this case the OSC A PW should go from MIN to MAX to MIN in a smooth movement.

I realize that i can set the POLY-MOD FILTER ENV to a lower value, but that's not a good solution as the parameter at the same time also can control FREQ A and FILT, so that will restrict the modulation for FREQ A and FILT.

I don't understand why the POLY-MOD FILT ENV is'nt able to be set to 12 o'clock allready, as the part of a square waveform used for PW and PWM normally is around 50%.
I guess this isuue is about the PW is affected with op to 100% of a full square waveform (2 times 50%). Allready at 0% or close to 0% and at 50% or close to 50% a PW will have no sound or sound very dirty/ unstable.
But why is there no sound when the value is over 50% then?  At least there should be sound no matter the settings i would think.

I would say something is wrong as it is, and should be like i describe or there should at least be sound at higher values for the POLY-MOD FILT ENV when it controls the PWA too.  At æeast only when passing 0 and100% of the PW there should be no sound. Am i right?
But should it pass those values? How do the hardware version works?

[LBH]

BTW: The WHEEL MOD has a similar issue for the PWMs. But instead of no sound, then there is a hold for the waveform modulation if you have full modulation on the wheel. The movement should be smooth and changing the waveform all the time, but it is'nt.
But at least there are sound all the time.

In generel i believe a look at the way the PWs and the PWMs functiond work in the synth.

[LBH]

I might add that i also find the PWA modulation odd when using the POLY-MOD OSC B as modulator.
(And when using the WHEEL_MOD to modulate the OSC B PW it's the same as described with OSC A PW.)

Something is wrong when modulating PWs.

This can't be correct behavior as see it.

[Borseti]

As frustrating as you might find this, it is actually correct behaviour. The original Prophet-5 allowed the Pulse waveforms to go all the way to 0%, thus reducing the sound to DC and no being audible. As for the Poly-mod section, this is also exactly like the original, and actually, once you get used to it and know what range to keep the PW knob in, you'll find that it's actually quite useful to be able to extend the PW range so much with the Poly-Mod.

In other words, I'd vote to leave it exactly the way it is for authenticity, and because it works fine on the original, so as long as you know the tricks to making the best out of it, you're okay!
Just my two cents. 

[LBH]

Thanks for responding Borseti.

Are you actually saying this - "if i go over the value 38% on the POLY-MOD FILTER ENV there is no sound from there and up" - is normal behavior in the example i described?
I can understand if there was no sound when at 100% in the example i describe. But not at 38%.
It max out at 19% if you have the PW set to start on a square wave.
To me it's seems wrong.

you'll find that it's actually quite useful to be able to extend the PW range so much with the Poly-Mod.

Can you please explain this in relation to the above? I don't understand.
How can it be useful if there is no sound from that low settings and up - and even lower depending on OSC As PW setting?
How do it extend? What do you mean by "much"?

To me the waveform is the length it is. The PW/PWM take place inside that length.

[LBH]

@Borseti - Researched a little more after my your input and my respons.
Prophet V don't work like the original after what i can find out.

I can find a useful usage in the preset "37-DelayedHarmonic", but for example in the original preset the attack sound more like as if you turn the filter decay down on Prophet V, and that to me indicate, that the sound from the pulse should be there all the time. To me there is a bug in Prophet Vs behavior.

Original manual including the original factory sound charts: http://www.synthfool.com/docs/SequentialCircuits/Prophet_Series/Sequential%20Circuits%20Prophet%205%20Owners%20Manual.pdf

Prophet-5 audio demos of the original factory sounds:
http://www.synthmania.com/Prophet-5%20(Rev.3).htm

Factory Sound "37-DelayedHarmonic":
http://www.synthmania.com/Sequential%20Circuits%20Prophet-5%20(Ver.3)/Audio/Factory%20Patch%20demos/File%201%20Programs/37%20Delayed%20Harmonic.mp3

There are other things like when using OSC B as a Poly-Mod modulator where it's punchy instead of smooth like in the original sounds.

[Borseti]

The audio demos sound the same to me!

So, it's helpful to remember that the PW is both negative and positive going, and this will dramatically change the way the PW ENV polymod behaves. So for example, try setting the PW knob on VCO 1 to roughly 9 o'clock, and listen to the ENV sweep, then move the PW knob to 3 o'clock. There's a big difference!

[LBH]

Hi Borseti,

I will not say the sounds sound alike. But yes i think i was fooled by some notes in the audio demo where there's no slow attack. (Do you know how that attack variation occour?)

Actually when reading the original manual closer for that sound, then they among other things write: "the PULSE-WIDTH is driven to 10 and generates to DC - in other words, no sound is generated."

So yes it's correct the PW can be driven to make no sound. I guess Prophet V do behave like the original, at least in the same direction. (Perhaps the parameter values/ effect at a given knob position could be better.)

I can also see there can be some possiblities in making sounds, when a delayed effect can be optained.

I guess one just have to take both the upsides and the downsides of this behavior into account when creating sounds.

Thanks for challenging me to find out about the authencity and the possibilities of this behavior.

[Borseti]

Hey, no problem!

I'm one of those people who wants a synth emulation to be EXACTLY the same as the original, because as soon as you start tweaking and "improving" things, you begin to stray away from the emulation side of things and end up in generic VA land. I remember reading that in the Prophet-5's manual. Interestingly enough, turning the PW all-the-way left will still result in sound, albeit 1% duty cycle, but this is useful for putting a thin layer of sound over another oscillator for variation. If Arturia had "improved" the design, you wouldn't be able to get that type of effect.

Arturia did a great job with the Prophet-V; I think it's their most authentic emulation out of the whole collection.

[LBH]

Hi Borseti,


Sorry - but:

what improvements are you talking about? And are the improvement something that destroy the original possibilities?

What is the difference between a emulation and something that's in what you call "generic VA (Virtual Analog) land"?

What is the difference between for example a digital application like Prophet 5 and something that's in generic VA land? Why is'nt  Prophet 5 and other applications that try to emulate analog behaviors allready in the generic VA land you don't wan't to be in?

Which features are in generic VA land, and which features are not? What define a generic VA land feature - and don't Prophet 5 have any already?


To me sound is the most important thing to emulate correct - especially for a synth unique sounds, that no other synth can sound like.
Also parameter ranges and settings that match the originals are important, and then added functionality to make the synth useful in modern workflow and different kind of music.
Emulations can still be better, even if some do quite well.

Nothing new in rebuilding or adding features and homemade boxes to synths to improve the functionality of the synth. Many have done that.
Oberheim SEM was intended as an keyboardless expander to other synths but also ended up as 2, 4 and 8 voices oberheim synths using a keyboard.
It was quite a great land many ended up in.


Cheers