Polyphonic Microtonal Synth
  • Hi,
    I was wondering if I can do this with Audulus. I want to be able to control the tuning of each note played on a keyboard on the fly. This is something the old Korg PS-3100/3300 had: for each of the 12 semitones on a keyboard you could alter its pitch individually, not only to create microtonal scales but I also want to make it so I can tweak that individual note specifically as I play a chord for example. Is this possible (and easy to implement) in Audulus?
    Thank you and best wishes,
  • Couple ideas that could work:

    - you could try modifying afta8's scale mapper to your needs: http://forum.audulus.com/discussion/453#Item_6 I don't think it would take much to alter the pitch spit out by each one, though his may just use a simple equal temperament calculation
    - you could punt, and go with MIDI from the outside: e.g. ScaleGen for iPad, though I'm not sure that supports direct MIDI output.
  • It's actually quite simple to do microtonal stuff with the scale mapper, just enter decimal values instead of whole integers.

    Anyway, heres a microtonal version of the scale mapper with a tuning dial for each note which will let you do what you want @Helder

    On a related subject it would be great if we could import scala files (.scl) into the keyboard node @Taylor, as quite a few tuning schemes have more than 12 notes to the octave.
  • this is great, thank you.
  • Thanks afta8, that is amazing.
    I also agree with you about being able to import scala and .tun files - that would be a great addition.
  • @afta8 from what I understand your patch deals with midi notes and cents. Do you think it would be possible to do it also with frequency directly (Hz)?
  • @Helder, yeah it can, here's a modification that takes Hz values in the inputs. This will double or halve the frequency entered dependent on which octave you play in relation to middle C. The note frequencies in this example are for Chromatic Tuning
  • Also here's the same patch but set up for Just Intonation..
  • Amazing. I will play with it when I have the time.(I'm on my mobile, can't check it now) Thanks for your work. I guess you set the JI via frequency (Hz) ratios directly, yes? Amazing stuff. Everything is possible now :)
  • Ok, I'm completely new to Audulus but had a chance to play with your patch. It seems to work pretty well (JI no beatings vs equal temperament). But one can't seem to be able to change the root notes or the math expressions in the patch...that one is set to C harmonics correct? Thank you. It would be easy to add knobs to the patch in Hz correct? I still have to learn this language...
  • Just an idea here but using an isomorphic keyboard like Monome (expensive) or Untz (much cheaper) would make doing this a breeze!
  • Yeah, I get some really nice phasing tones with the JI on certain chords.. never really given JI and the whole 432 tuning much time before but I can hear why some people prefer it now..

    I took the root note setting out of this version to keep it simple (and it was confusing me a little) but I will have a go at adding it in.. I presume changing the root note on the Hz version is the same as transposing the input notes.

    As for the math expression nodes I think you need to get the in app upgrade to be able to edit them. As you can see I am using them to get the frequency ratios on the JI patch however you could do the same with the stock math nodes if you don't want to buy the upgrade.
  • @biminiroad, isomorphic what??
    Ok just googled it... very nice... I want this one: http://www.rogerlinndesign.com/linnstrument.html

    Not sure how you could do microtonal tunings with one though, isn't the midi spec equal temperament?
  • You can assign a pitch to each key. For Monome and Untz there is coding you do - it's not plug 'n' play. In Audulus you'd just do something like if midi note == x play x microtone.
  • @afta8 I had a chance to play a little bit more with your ScaleMapper patch in Hz and JI and it is really wonderful. I find it interesting that you were not "into" JI at all but still managed to program this so quickly! Yes, indeed one can feel a difference between well-temperament and JI tunings played in the same key - very noticeable. It's physics :) I find JI much more pleasant.

    A couple of questions: in your JI patch, the first number corresponds to the root note or key of the whole tuning, yes? So if you change that you "transpose" the whole tuning, right? The expressions "C C*16/15" for example take that first constant (the root note) and applies that ratio, correct? (BTW you set the pitch of the root note to 259.2 - that is *almost* middle C, normally 261.6, as you have in the other patch; maybe a typo). You are right, I can't change the expressions or the frequency of the root note before I buy the math upgrade - which I might do just for this! Seems worth it :)

    An idea I had: in theory, you could maybe program a patch where you would set a pop-down menu (or switchs) with all the possible root notes/keys. Like this you could play in JI in all possible keys on the fly, maybe. You could maybe midi learn those switches so you could change scales as you play. Interesting possibilities I think, but I'll need to learn a little bit more about it. I saw this video done with Cubase 7 that I found very interesting: http://youtu.be/8yAohDrNTgE ; here keys are changed via a dedicated midi track (a unique feature of Cubase I think) and it sounds lovely in JI.

    And a final question: how did you set it to play in octaves? What is the relationship between the root note and the next octave higher? Is it 2:1 and then the pattern repeats with that new note frequency as the root note for that higher octave?

    Thanks again and congratulations on your programming skills!
  • @Helder, thanks for the feedback :)
    I've been playing with it some more, it is indeed quite pleasant, almost angelic?! not sure if thats the right word.. but yeah sounds nice. The only reason I haven't really got into it was compatibility with other plugins I use in my DAW not all of them can be tuned right.. I think I will use it in Audulus only compositions..

    I had the basis for the patch already and with a bit of Googling I got the ratios for JI and plugged them in. And yes you are right, the first number corresponds to the C note to which the ratios are then applied, the reason I went with 259.2 is because that was the only way to get exactly 432 for the A note using those ratios. I'm not sure which is right really... I guess C can be whatever you want really?

    I would recommend getting the maths node, that and the custom nodes are the 'must haves' IMO, then you can go crazy with this!

    I had a look at the video, I think I know what you mean.. we don't have drop downs in Audulus but I think it could be done with switches.. To be honest I need to give some more thought on how to do root keys when using the 'Hz as inputs'. I had it nailed when using note numbers, but using Hz is a little more confusing.. I'll have a go when I have some time, but I am quite keen on developing something thats lets you change keys on the fly to do chord progressions but my knowledge of music theory is limited.. will get there eventually.

    As for the relationship to octaves, the frequencies just double for every octave you go up (or halve when going down). There is a math node in the sub patch that does the calculation if you want to modify it.

    Glad you are enjoying it :)
  • Just worth reiterating on this thread but if you attach an LFO with a low amplitude and frequency to the root note (just delete the number and plug the LFO output in that spot) it makes for a really beautiful totally original-sounding effect.