[sdiy] Quantizer project.. incoming CV's switching point to change to quantized output CV's ...
jpdesroc at oricom.ca
Tue Jul 6 16:27:38 CEST 2021
Sorry Richard but I lost you in many places
in your very detailed explanation..
So far I aim to use C scales only.
To transpose to other keys I would just change the incoming CV’s offset
with semitones steps. Primitive way to do this but easy.
Thanks anyway for your knowledge.
De : Richard Wentk [mailto:richard at wentk.com]
Envoyé : 6 juillet 2021 09:35
À : Jean-Pierre Desrochers
Cc : David G Dixon; SDIY
Objet : Re: [sdiy] Quantizer project.. incoming CV's switching point to change to quantized output CV's ...
I would ignore microtonal options because they’re impossible to set up and control on a device with a tiny panel, and hardly anyone uses them.
So you get 12 steps -> oct with hysteresis on input, producing a numeric semitone + octave, through lookup tables which translate semitone + oct into various output scales.
Don’t forget scales should be transposable. If you have semitone + oct on input that’s easy with a bit of extra arithmetic.
There are actually two kinds of transposition - modal and in-scale.
You do one before the lookup table and one after.
Quantise -> modal transpose -> scale lookup -> scale root transpose.
E.g. +n -> lookup to C Major -> +0 -> Various modes of major
You’re moving up and down a note range in the same scale with different lowest (‘root’) notes.
+0 -> lookup to C Major -> +n -> Various major scales
You’re selecting different major scales
Of course you can combine these options too. Voltage control of both separately is *very* useful for complex sequencing.
This looks super-complicated, but if you use C scales only in your lookup you can select different roots/modes with the transpose options.
So you don’t need separate lookup tables for C major, D major…. C Dorian, D Dorian.. and so on. Just one for each scale type, and a bit of logic to select the transpositions.
This also works for “short” scales like Pentatonic, triads and other chord shapes, and so on.
On 6 Jul 2021, at 01:07, Jean-Pierre Desrochers <jpdesroc at oricom.ca> wrote:
This a very good point..
And the "equal voltage invervals between each note" approach
seems easier to implement in code using a lookup table with
a ‘definition’ for each scale..
This approach will effectively give a scale the same ‘luck to be played’
for all of its notes. And is less picky on the threshold voltage precision.
I’ll keep note of this. Thanks !
De : David G Dixon [mailto:dixon at mail.ubc.ca]
Envoyé : 5 juillet 2021 19:43
À : 'Jean-Pierre Desrochers'; 'SDIY'
Objet : RE: [sdiy] Quantizer project.. incoming CV's switching point to change to quantized output CV's ...
I don't know diddly-squat about code, but I've been working on an analog quantizer with logic for generating various scales, and I must say that I'm a strong advocate of the "equal voltage invervals between each note" approach.
Of course, for the chromatic scale, this is a no-brainer: 83.33 mV per note. However, if you want to quantize a major triad, I would use 333.33 mV per note. For a major scale, 142.86 mV per note. Et cetera.
Why? Because if you are running the scales or arpeggios by playing the quantizer with a triangle wave LFO, you will want each note to last for the same amount of time. Any other approach will impose a rhythm that will favour notes that are farther away in pitch from the others.
As usual, the right answer is the musical one, not the technical one.
From: Synth-diy [mailto:synth-diy-bounces at synth-diy.org] On Behalf Of Jean-Pierre Desrochers
Sent: Sunday, July 04, 2021 10:35 AM
Subject: [sdiy] Quantizer project.. incoming CV's switching point to change to quantized output CV's ...
[CAUTION: Non-UBC Email]
I'm starting a CV quantizer design and am wondering
about the following things:
Let's assume a normal quantized semi-tone scale:
All the incoming CV's are quantized to semi-tones like this:
incoming CV 'around' C, output quantized CV -> C
incoming CV 'around' C#, output quantized CV -> C#
incoming CV 'around' D, output quantized CV -> D
and so on..
12 equally spaced output quantized intervals. OK.
But if the quantized scale output is a TRIAD like
C-E-G-C-E-G-C, etc... ( 3 quantized intervals)
where are the switching bounderies of each incoming note CV's
to change to the next outputed quantized note ?
This question is for ascending and/or descending notes..
Same question for a quantized PENTATONIC major scale output like
C-D#-F-G-A#-C-D#-F-G-A#-C, etc.. ( 5 quantized intervals)
I would think of dividing the octave range with
equal intervals with the number of intervals
inside the actual quantized scale..
That's 3 intervals
1 octave = 1 volt
so 1volt/3 intervals = 0.333v between each quantized notes (??)
PENTATONIC major scale C-D#-F-G-A#-C
That's 5 intervals
1 octave = 1 volt
so 1volt/5 intervals = 0.20v between each quantized notes (??)
But... I don't think that is working this way..
I think I must keep the incoming CV interval sizes
and use them for the quantized switch points.. (???)
Your opinion on that ??
Synth-diy mailing list
Synth-diy at synth-diy.org
Selling or trading? Use marketplace at synth-diy.org
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the Synth-diy