Getting Paraphony to sound like Duophony

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Libertine Lush
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Getting Paraphony to sound like Duophony

Post by Libertine Lush » Thu Aug 20, 2015 5:49 am

The Sub 37 is my first experience with Paraphony. Are there ways of getting the paraphony on it to sound more like duophony?

I've noticed that if I set both Osc. to the same pitch and KB CTRL to Low or High that makes quite a difference.

Thanks for any insight.

ChiLam
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Re: Getting Paraphony to sound like Duophony

Post by ChiLam » Thu Aug 20, 2015 7:50 am

The Sub37 is both Duophonic and Paraphonic - as I understand it. Duophonic because it can address each oscillator separately according to the High or Low note priority setting. Paraphonic because each oscillator must pass through the same single filter and amp envelope. This is what happens with the Sub37 in Duo mode or Mono mode.

Perhaps you are confusing Duophony with 2 voice Polyphony? This would require each voice, made up of X number of oscillators, to have independent filters and envelopes.

MoogProg
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Re: Getting Duophony to sound like Polyphony

Post by MoogProg » Thu Aug 20, 2015 8:21 am

Re: Getting Duophony to sound like Polyphony
^Edited the subject to reflect the question which I'll try to answer.

Duo mode on the Sub37 is not like the polyphony we would get from something like an OB-X or a Juno106, those are polyphonic synths where each voice has its own OSC, ENV, and Filter. The voices can come and go as they please, without being constrained by the other voices. Sub37 Duo Mode constrains the OSCs by piping them both through the same ENV and Filter, such that there is no way to independently trigger each voice. (Edit: Demon_Dan helpfully offers some tips below on how to achieve a degree of independence with the OSCs. Thanks Dan!)

It is easiest for me to think of Duo Mode as something similar to a double-stop played on the violin, a typically monophonic instrument, but one where we can add a second voice occasionally and only within certain limits set by our bow length, bridge curve and finger reach. Still, great stuff comes out of this limited technique. Another helpful analog for me, is to play Duo Mode patches like an Organ, with lots of slurs and movement and ample use of the footpedals to sweep the filter and volume.

Expecting Duo Mode to behave like Polyphony is (to my thinking, at least) a set-up for ideas that won't work out as expected. I can think of no way to play VH's Jump on a Duo or Paraphonic synth, only on a Polyphonic synth.
Last edited by MoogProg on Fri Aug 21, 2015 12:05 pm, edited 1 time in total.

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stiiiiiiive
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Re: Getting Duophony to sound like Polyphony

Post by stiiiiiiive » Thu Aug 20, 2015 9:19 am

MoogProg wrote: It is easiest for me to think of Duo Mode as something similar to a double-stop played on the violin, a typically monophonic instrument, but one where we can add a second voice occasionally and only within certain limits set by our bow length, bridge curve and finger reach. Still, great stuff comes out of this limited technique. Another helpful analog for me, is to play Duo Mode patches like an Organ, with lots of slurs and movement and ample use of the footpedals to sweep the filter and volume.
Excellent analogy. I tend to think like you that such constraints push towards a creative way to play an instrument.
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_DemonDan_
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Re: Getting Paraphony to sound like Duophony

Post by _DemonDan_ » Thu Aug 20, 2015 10:56 am

Libertine Lush wrote:Are there ways of getting the paraphony on it to sound more like duophony?
Hi LL,

The key thing to hinting at Duophony is to MacGyver ways to control amplitudes of OSC 1 and OSC 2 separately.

This is possible because there are several ways to independently control the amplitudes of OSC 1 and OSC 2, as well as their ON/OFF states in the MIXER.

Since there is nothing like this for the FILTER section, you have to first give up any hopes and dreams of having different filtering for each. As such, it's best to try all of these experiments with the FILTER CUTOFF all the way up. (Later, you can find musical ways of using the Filter that won't diminish your Duophonic illusions.)

Here are some ideas from my previous posts on this subject:

The current Sub 37's CV MAPPING feature (in the GLOBAL MENU) allows you to use a Sustain Pedal footswitch in the GATE CV INPUT jack to control a selected destination, including the OSC 2 ON parameter.

Depending on whether you use a Normally Open (N.O.) or Normally Closed (N.C.) pedal, you'll be able to turn OSC 2 ON or OFF at will. (You can also change the GATE CV IN's polarity using the GATE INVERT parameter, but using the little switch on the bottom of the pedal is faster.)

This is a reasonable solution for those who don't want OSC 2 to join OSC 1 when you go from playing two notes to only playing one note. Simply use the Sustain Pedal to make OSC 2 sound only when you want it to.

---------------------

There is a cool trick that I often use to gain independent control of the amplitude of each Oscillator.

If you look at page 51 of the Owner's Manual, you'll see all of the possible Modulation Destinations, which include independent Levels for OSC1, 2, SUB, NOISE, and EXT IN.

By using Filter ENV (F.EG) as the Source and, let's say, OSC 2 LEV as the Destination, you could create the appearance of having separate volume envelopes for each Oscillator.

BUT... you have to remember that EVERYTHING still goes through the final AMP and its ADSR. So... Use this envelope hack on the Osc that's going to have the shorter Release Time (and/or the longer Attack Time) so that it happens within the envelope times of the "real" ADSR times.
_ :twisted: _DemonDan_ :twisted: _

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Libertine Lush
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Re: Getting Paraphony to sound like Duophony

Post by Libertine Lush » Fri Aug 21, 2015 2:14 am

ChiLam wrote: Perhaps you are confusing Duophony with 2 voice Polyphony?
Indeed I am. I assumed Duophony was just a more syllabically friendly way of saying 2-voice Polyphony.

Thank you, ChiLam and MoogProg, for the explanations!

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Libertine Lush
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Re: Getting Paraphony to sound like Duophony

Post by Libertine Lush » Fri Aug 21, 2015 2:34 am

_DemonDan_ wrote: Here are some ideas from my previous posts on this subject...
Thanks so much for all of that. I'm gonna copy/paste it for reference later on.

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_DemonDan_
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Re: Getting Paraphony to sound like Duophony

Post by _DemonDan_ » Mon Aug 24, 2015 9:25 am

Libertine Lush wrote:I assumed Duophony was just a more syllabically friendly way of saying 2-voice Polyphony.
That is also my understanding.

I believe that Duophony means true 2-note Polyphony (where each Osc gets its own VCF and VCA).
_ :twisted: _DemonDan_ :twisted: _

ChiLam
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Re: Getting Paraphony to sound like Duophony

Post by ChiLam » Mon Aug 24, 2015 11:07 am

Not according to the venerable Mr Marc Doty!

PARAPHONIC vs. POLYPHONIC
It's one of my pet peeves, actually. There seems to be some extensive confusion about what these terms mean, and what they mean in relation to each other.
Even the Wiki page states something ridiculous about "true polyphony."
So, I'm here to set the record straight (in regard to synthesizers).
Monophonic/Monophony: This synthesizer, triggered from a keyboard, can only play one note at a time. Now, depending on the amount of oscillators, more than one note may be heard... but all of these notes will move in tandem when different single notes are played on the keyboard.
Duophonic/Duophony: This synthesizer, triggered from a keyboard, can only play two notes at a time. This term came into being in regard to synthesizers at the point where synthesizer oscillators were modified to be either "low note priority (the lowest voltage is played, all others are ignored)," or "high note priority (the highest voltage is played, all others are ignored)." Synthesizers like the ARP Odyssey, the Moog Sonic Six, and some versions of the ARP 2600 are duophonic. You can play two notes at a time, one for each voltage. Of course, you also need at least two oscillators.
Polyphonic/Polyphony: This synthesizer, triggered from a keyboard, can play two or more notes at a time. Yes, I know... that overlaps with the term "duophonic," but these things can't be helped. "Polyphonic" is a very general term.
In regard to analog synths, there are two types of polyphony.
There is top-octave divide-down polyphony, where the top octave of keys has its notes provided by 12 fixed-pitch oscillators and those frequencies are divided in half to aquire each subsequent descending octave. That means the synthesizer has 12 oscillators, and 12 dividers per octave after that. Every SINGLE note can be played at the same time on this synthesizer. This is, by definition, "true" polyphony. It started in 1939 with the Hammond Novachord, and has been used extensively in a variety of synthesizers up until the 1980s.
There is "limited, but individually-articulated" polyphony. This is polyphony where a microprocessor scans which notes are played when, and applies that information to the available oscillators. This type of polyphony came about with advances in microprocessor technology that made microprocessors less expensive and more available in the 1970s. It allows you to have more control over the articulation of each note, but severely limits the amount of notes that can be played at once. The Sequential Circuits Prophet 5 and the Yamaha CS-80 are examples of this method. The limitation comes in because each note needs a variable oscillator... or even two. And those are expensive.
Of course, with digital technology, polyphony increased from 2 notes to 4 notes to 8 notes to 16 notes, and etc. More powerful computers means more powerful voice allocation and less expensive digital oscillators.
[Note: there is actually a type of polyphony that was created by Harald Bode back in the 1930s which allows electric note allocation, but apart from the Warbo Formant Organ, I don't think it has been implemented anywhere else... I'm really curious about it]
Okay, and that's it. That's the end. Those are the types of polyphony.
"But wait!" You say... "What about PARAPHONY! Isn't that a form of fake or not true or not-quite-real polyphony?"
No, it most certainly IS NOT. It really has NOTHING TO DO WITH polyphony. In fact, every monophonic is ALSO paraphonic.
I know you're running to your favorite online dictionary right now... but I'm going to plow ahead. smile emoticon
"Paraphonic" is a term that has to do with articulation... not a term that has to do with how many notes a synth can generate. A "paraphonic" synthesizer is one where all of the notes generated... from 1 to 1,000,000... go through a single filter and VCA combination. That's it. That is what "paraphonic" means. It's just more noticeable when you're trying to articulate polyphonic passages.
A synthesizer like the ARP Omni is paraphonic. It has a divide-down polyphony scheme, but all of those notes, and every triggering of those notes, is forced through a single filter and VCA. What does this mean? It means you can't have each new note played featuring new filter articulation without having that same articulation occur on the notes you're holding. Or, it means that new notes get articulation, but old notes get nothing. Is that awesome? Well, not really. In fact, people kind of hate it, sometimes. They want each note to trigger a filter and VCA. Which is, I must point out, just like a piano. People really like how each note played has its own volume and filter articulation.
Just like, say, a Prophet 5 or a Memorymoog. But the problem with those is that you run out of notes quite quickly. In the Prophet 5, you only have 5 notes to play before you run out of polyphony. What kind of polyphony is that? SEVERELY limited polyphony. But... people tend to favor it because they like the articulation more than they like the note-count.
Of course, you could always go the route of the Korg PS-3100. It is divide-down, but instead of going the paraphonic route, it has A FILTER AND VCA FOR EVERY SINGLE ONE OF ITS NOTES. Yeah, that gets expensive fast... which is why most manufacturers didn't take that route.
And that is what it comes down to. "Polyphony" is how many notes a synth can play at once. "Paraphony" is the instance where those notes are directed through a single filter/amp combination. Synths can be polyphonic AND paraphonic. Synths can even be monophonic and paraphonic. But the only "real" polyphony is when every note can be played at once... whether you seek individual articulation or not. Instead of saying things like "real polyphony," we should describe full polyphony with full articulation with a term like "ideal polyphony."

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