Quantizer idea

[doctorvague]

Goals:
4 discrete channels of quantization with as much immediate random access to scales, transposition , octaves etc. as possible. Individual notes accessible on the fly to build scales, chords, bass lines etc. Octave switching and swap-switches add to the immediate experience. Can you feel yourself massaging those toggles yet?




A 4-width Frac-rack implementation.

This design is a 4 channel quantizer with dual controls. Each of 4 CV inputs is separately quantized, selectable between A and B quantizers and transpose controls. Scale, referenced to C, is selectable on the fly and mutes with all switches off. For convenience, inputs 1 and 2 are normalled together as are 3 and 4. With separate inputs on either 1-2 or 3-4, a swap function enables the CV input signal to be swapped with the adjacent quantizer and output. Separate 3 position octave switches for the A and B quantizer control sections are provided as well as octave switches on each output. Multed outputs for convenience. Transposition is via LED lit momentary switches which are mutually exclusive and are represented visually with the same keyboard interface.

Methods of use
With a minimum of 2 CV control sources you would use inputs 1 and 3 which are normalled to channels 2 and 4. Set Channel 1 and 3 to A, 2 and 4 to B. Using all 4 CV inputs enables the swapping of inputs on the fly. For a simple example let's say the 4 outputs are sent to 4 oscillators and then wherever your patch cords may take you. Actually the very simplest setup is just set all 4 channels on the A section and control all 4 CV's from the A quantizer section. Nothing wrong with that when trying to keep it simple.

I would call this a literal approach- leave the transposition button at C for a baseline. Tune all oscillators to C - easy to reference using just the C note switch. Now the quantizer is giving you the literal quantization and what you see with the toggle switches is what you get. If you have all black key toggles on it's black key CV's being output for sure.You're playing the toggles much like a keyboard at that point. Sounds like fun to me.

There are at least other 2 ways to set up the quantizer for a song, for example, in E major beside the literal approach above. One is, flip the C switch only, on the quantizer and tune the oscillators to E, etc. The other way is to leave the osc in standard C tuning and use the transposition E button. It's a matter of musical preference and/or convenience in the moment, but you have both options and more.

You can instantly switch between any 2 scales, or this module could just be used as a glorified octave switching system. A sad day if that's all the damage you can do but hey switch yer octaves then... wee-ooo weee-ooo...

Musical examples

Quantizer A: Notes: C F G • Intervals: 1 4 5 - flip each note off once in a while. Switch D on now and again.
Quantizer B: Notes: Eb Bb • Intervals: b3 b7 - adding in Ab, b6 occasionally for that sad m6 sound. Or swap the Eb for E to take it major.
When musically inspired, transpose everything up by hitting both transposition switches of choice at once. I really wanted the interface to have that sort of immediacy, i.e bump the whole thing up to Bb or C# right NOW. Two finger, 4 part transposition, no waiting. Boo-yah- other methods!

With everything tuned to C you could play in G by leaving the transposition switch in C and turning on note switches:
Quantizer A: Notes: G D F# Intervals: 1 5 7
Quantizer B: Notes: A B C# E Intervals: 2 3 #4 6, again switching the 6 in and out...
That adds up to a G Lydian modefor anoyone interested.

Hope this lights some musical fire-ideas because it certainly has mine.
Thanks to Bearblock for the interface inspiration.

Options:
A and B trigger output jack (trigger at quantizer note change).
Input CV attenuators for scale sculpting/scaling and octave mayhem.
Outputs could could be swapped vs inputs - there are different musical effects from both...

Did I neglect to mention I haven't a clue how implement this design??
Oh look, a squirrel...
Phil

[urbanscallywag]

Sure looks pretty.

I'm a little confused about what it does though (my weak musical terminology may be the reason).

Say I had a pot that output 0V at 1 end and 5V at the other. And I had only the C switch turned on as you mentioned. So as I turned the knob clockwise I would hit C0, C1, C2, C3, C4, and C5? And if I flicked on the D switch and did the same thing I would get C0, D0, C1, D1...? That's neat, I think there's something like that in Ableton for MIDI notes.

I don't understand the octave switches next to the A and B sections.

Cool concept, and again it looks great!

[doctorvague]

[Funky40]

[urbanscallywag]

Oh, those switches are 'global' octave switches. Again, cool idea.

"Quantize" makes sense to me from an engineering perspective. The project could [probably] be done with an R2R ladder (ADC), processed with discrete logic, and converted back to analog using an R2R ladder (DAC). But an R2R into a microcontroller into an R2R would be my method. You could even have presets that way.

[neandrewthal]

I want it. Is it actually going to happen or should I go with the simple MFOS one for now?

[doctorvague]

It's just a concept. If I had the electronic chops to do it I'd already be working on it. I would definitely throw a decent size pile of money at it though. I had a feeble hope this might hold some interest of those who could pull it off but it appears not. Oh well it's fun to dream.

edit: oops I missed a couple of posts above - I've been working since about 5Am and kinda cross-eyed, plus I'm not getting all my email notifications either for some reason. Thanks for the ideas. I've read about R2R's - I'll have to read up on them again and also have a look at he MFOS as soon as I have time. I have read about the CGS one, but I don't understand how it works to be honest.

[neandrewthal]

I see. I'm trying to figure out how to turn the MFOS one into something like this. And by "figure" I mean find someone smarter to tell me if it's possible and exactly how to do it.

I like the Idea of having 4 quantizers with 2 sets of controls, and the keyboard style scale selection is what I'm really after.

[doctorvague]

I forgot to mention about the A and B octave switches - another reason I included them is so you could transpose down as well as up. Let's say you have the transpose button at C and you want to transpose down to Bb instead of up. Just hit the Bb button and the octave down switch at the same time and everything will lower by a whole step.

[urbanscallywag]

That makes more sense. I didn't even see the transpose buttons, I thought they were LEDs!

I thought about it and decided flipping 2 or even 4 octave switches at the same time wouldn't be too bad, but the transpose function makes sense.

[doctorvague]

I just remembered another scenario I forgot to put in my original post. By having 2 discrete quantizer controls, you can work ahead using it a bit more like presets. Say your first section of music is in E Major and you have that set up on quantizer A and all 4 outs assigned to A. The next section of music uses some other scale - say G minor. So you set up your G minor scale on section B and flip all 4 assignment switches to B whenever the music dictates. Should be a pretty easy move with 2 hands the way the switches are positioned. A friend and I jam live like that - while jamming we call out "G Lydian" or "Black keys" or "C Whole-tone" and that sort of thing. This kind of has that functionality if you choose to use it that way. I realize presets might appeal to some people but I already have a Modcan dual quantizer and as cool as it is, I find myself a bit frustrated occasionally trying to remember where the Whole tone scale is out several dozen presets available. Plus sometimes you want to build from say just a root note, then root plus fifth, then add the fourth, etc, or the opposite on a breakdown where you want to strip away notes down to the root note for example. The best method I see for that is random access. Plus as a personal bias, I'm into various scales and like having full control.

Below are some scale charts we use to jam with that I put together a couple of years ago. Again I meant to post this earier and spaced it out. The keyboard charts would translate perfectly to this quantizer interface.

==================================
Here are some links to zipped folders of PDF scale diagrams in all 12 keys, for both guitar and keys. Each link is 4MB or less.

The first are various scales, modes, modes of modes, for keyboard etc
http://idisk.mac.com/doctorvague/Public/Misc/Scales-Modes-12Keys-Kybd.zip

These are various ethnic scales, like Hungarian, Chinese, Hindu, etc.for Keyboard:
http://idisk.mac.com/doctorvague/Public/Misc/EthnicScales-12Keys-Kybd.zip

Misc scales and modes for guitar:
http://idisk.mac.com/doctorvague/Public/Misc/Scales-Modes-12Keys-A-I-Gtr.zip
http://idisk.mac.com/doctorvague/Public/Misc/Scales-Modes-12-Keys-J-L-Gtr.zip
http://idisk.mac.com/doctorvague/Public/Misc/Scales-Modes-12Keys-L-Gtr.zip
http://idisk.mac.com/doctorvague/Public/Misc/Scales-Modes-12Keys-M-Z-Gtr.zip

Ethnic scales for guitar:
http://idisk.mac.com/doctorvague/Public/Misc/EthnicScales-12Keys-A-H-Gtr.zip
http://idisk.mac.com/doctorvague/Public/Misc/EthnicScales-12Keys-I-Z-Gtr.zip

And here are some charts in all 12 keys that show the major and minor triads contained within each scale. The dark rectangles show the triads contained in the scale. The alternating light and dark horizontals are just to help your eye read across the page.

http://idisk.mac.com/doctorvague/Public/Misc/Triads-In-ScalesPDF.zip

Some links to scale web sites, calculators etc.:
http://www.xs4all.nl/~huygensf/doc/modename.html

[urbanscallywag]

I would add a pot (and maybe an LED) next to each of the voltage inputs to serve as an offset function and also to be able to "tune" the input voltage so it doesn't bounce back and forth between quantization levels.

[doctorvague]

[doctorvague]

[doctorvague]

[neandrewthal]

http://www.musicfromouterspace.com/analogsynth/VOLTAGEQUANTIZER/VOLTAGEQUANTIZER.php

[urbanscallywag]

[doctorvague]

[blue hell]

[doctorvague]

[Scott Stites]

Whatever it is, it's a very cool idea.......

[urbanscallywag]

Thanks for the Doepfer information, doesn't sound like there's much in there! Obviously enabling and disabling various semitones would add a lot of logic to it.

The hysteresis problem is interesting. That's why I suggested a tuning pot next to the input. You could have an LED light when the input voltage is comfortably in the threshold for just 1 quantization level.

[doctorvague]

[Scott Stites]

It would also feed a Klee nicely (external range in).

[sneakthief]

Please don't let this thread die!

What can we do to proceed with this project?

Doctorvague: I know you like how your doepfer works, so do you think it's alright to use that as a starting point and post the relevant parts of the schematic? (Heck, they've "borrowed" a lot of work from others along the way)

In any case, I've been thinking about quantizers for a long time... and there have been several threads on here with various designs, mostly simple chromatic ones.

The more I think about having switches to immediately pick the scale, the more I realize how brilliant and useful it would be for composition and performance.