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a-113 subharmonic generator

2018-06-30 by justintonation29@gmail.com

For many years I have been interested in microtonal music. One of my favourite composers is Harry Partch who developed an intonational system that used 6 notes chords (hexads) derived from both the harmonic and subharmonic series. The harmonic chords were reduced into a span of a almost an octave and a half rather than the 4 octaves that the chords would have spanned if they were not octave reduced. If this does not make sense, Partch's otonal (harmonic series) chords had the following ratios 1/1, 5/4, 3/2, 7/4, (2/1), 9/4, 11/4. If this chord was not octave reduced it would have the following ratios (in ascending order) 1/1, 3/1, 5/1, 7/1, 9/1, 11/1. Partch also used subharmonic chords which he called utonal (from the word undertone). The utonal chords are mirror images of the otonal (from the word overtone) chords. For the mathematically inclined the ratios are in descending order 2/1, 8/5, 4/3, 8/7, (1/1), 16/9, 16/11. Again if these chords were not reduced to an octave and a half span they would have the following ratios (and different order): 1/1, 1/3, 1/5, 1/7, 1/9, 1/11.
For more information regarding Partch's chordal structures see this page http://www.chrysalis-foundation.org/Partch-s_Diamond.htm

I am sure you are wondering what this has to do with the Doepfer A-100 system? Well, I currently use a Doepfer A-198 Trautonium-Manual / Ribbon-Controller with a Tubbutec microtonal CV quantizer. I feed the quantized CV to an oscillator and then send the oscillator audio to an Erthenvar patch chord module which has an Equal Tempered, just intonation, and Harmonic/Subharmonic modes. I use an doepfer A-143-1 to a quad vca for creating arpeggios from the chord outputs. While this setup is good, I wish to have the freedom to choose the chordal mixes available and to change them during performance. I believe that the A-113 subharmonic generator module may be able to do this. Does this module only do subharmonics or are harmonics also available? If the a-113 can only do subharmonics, can they be octave reduced ? Also is there a limit to the divisor (or multiplier if harmonics are possible). By this I mean is it possible to divide by 11, 13 or 17 etc ?

If the subharmonics cannot be octave reduced then is there another way to do this? Perhaps a precision adder or something could help?

Sorry for the long post

Cheers,

Justin

Re: [Doepfer_a100] a-113 subharmonic generator

2018-07-02 by Florian Anwander

Hi

I can answer three of your questions

Am 30.06.2018 um 10:52 schrieb justintonation29@gmail.com [Doepfer_a100]:
> I wish to have the freedom to choose the chordal mixes available and 
> to change them during performance. I believe that the A-11 3 
> subharmonic generator module may be able to do this. 
You can store different division settings and step with manually or by 
external gate signals through those stored settings. You cannot jump 
directly to a setting.

> Does this module only do subharmonics or are harmonics also available? 
Only subharmonics

> If the a-113 can only do subharmonics, can they be octave reduced? 
You could let the master clock run at a high frequency and divide the 
signals from the individual outs with an external divider - but these 
are then rectangles and not saws.

> Also is there a limit to the divisor?
24


Florian


-- 
http://www.florian-anwander.de

AW: [Doepfer_a100] a-113 subharmonic generator

2018-07-02 by yahoo@doepfer.de

Hello,

module A-113 offers only subharmonis in the range 1/1...1/24 derived from an
external VCO (e.g. A-111-3) and cannot be octave reduced. You find a
detailed desciption of the module on our website:

www.doepfer.com > English > PRODUCTS > A-100 > Module Overview > A-113

Best wishes
Dieter Doepfer

Show quoted textHide quoted text

> For many years I have been interested in microtonal music. One of
> my favourite composers is Harry Partch who developed an
> intonational system that used 6 notes chords (hexads) derived
> from both the harmonic and subharmonic series. The harmonic
> chords were reduced into a span of a almost an octave and a half
> rather than the 4 octaves that the chords would have spanned if
> they were not octave reduced. If this does not make sense,
> Partch's otonal (harmonic series) chords had the following ratios
> 1/1, 5/4, 3/2, 7/4, (2/1), 9/4, 11/4. If this chord was not
> octave reduced it would have the following ratios (in ascending
> order) 1/1, 3/1, 5/1, 7/1, 9/1, 11/1. Partch also used
> subharmonic chords which he called utonal (from the word
> undertone). The utonal chords are mirror images of the otonal
> (from the word overtone) chords. For the mathematically inclined
> the ratios are in descending order 2/1, 8/5, 4/3, 8/7, (1/1),
> 16/9, 16/11. Again if these chords were not reduced to an octave
> and a half span they would have the following ratios (and
> different order): 1/1, 1/3, 1/5, 1/7, 1/9, 1/11.
> For more information regarding Partch's chordal structures see
> this page http://www.chrysalis-foundation.org/Partch-s_Diamond.htm
>
> I am sure you are wondering what this has to do with the Doepfer
> A-100 system? Well, I currently use a Doepfer A-198
> Trautonium-Manual / Ribbon-Controller with a Tubbutec microtonal
> CV quantizer. I feed the quantized CV to an oscillator and then
> send the oscillator audio to an Erthenvar patch chord module
> which has an Equal Tempered, just intonation, and
> Harmonic/Subharmonic modes. I use an doepfer A-143-1 to a quad
> vca for creating arpeggios from the chord outputs. While this
> setup is good, I wish to have the freedom to choose the chordal
> mixes available and to change them during performance. I believe
> that the A-113 subharmonic generator module may be able to do
> this. Does this module only do subharmonics or are harmonics also
> available? If the a-113 can only do subharmonics, can they be
> octave reduced ? Also is there a limit to the divisor (or
> multiplier if harmonics are possible). By this I mean is it
> possible to divide by 11, 13 or 17 etc ?
>
> If the subharmonics cannot be octave reduced then is there
> another way to do this? Perhaps a precision adder or something could help?
>
> Sorry for the long post
>
> Cheers,
>
> Justin
>
>
>
>
>