Frequency dividers and sequencing, how to program 1/4 notes?

Yes I agree, I’ll usually turn to bogaudio offset for this task.

But there is:

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Here is my crude attempt at a sequencer:

First row is step length, second row is gate length, and third row is ratchet. The quantizers just round everything off to 1, 1/2 or 1/4 multiplying or dividing. By adding more notes on the quantizer you can add more sub divisions, but the quantizer needs to be set to just intonation.

Here is a test I did using this idea:

[Expeditions in Space and Time - #14 by auretvh]

A second sequencer needs to be added for pitch, velocity, etc.

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It took me a while to figure out what the ratchet CV was doing - which is weird, because I was already thinking about the possibility of using multiple LFOs.

Not sure how well it applies in your patch, but it might be easier to use OCT instead of QNT to perform rounding. Simply patch your signal to the CV input, leaving the V/Oct input empty, and it will round your signal to the nearest integral volt. If needed, you can then attenuate to get nice fractional values, without having to worry about just intonation.

In case others don’t know how easy this is, I’ve shown how this can be done below. the top SEQ 3 is the master, and the bottom will always remain in sync (disregarding the 1 sample delay). Note the bottom STEPS is set to 1, and the STEPS CV to 100%. The only trick is to make sure they start out with the same RUN state. Once synced, they will remain in sync as long as you never interact with the bottom RUN or RESET buttons, or STEPS or STEPS CV knobs.

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Of course, OCT makes so much more sense. Thanks for taking the time to review it Dave. I just like the idea of using a quantizer because of that experiment in the link above. But in this case, it’s pointless. I love trying to figure out things like this in VCV, like a type of a challenge. Which is also why I appreciate all the work you have put into the fundamental constructs. It’s quite a bit of work. :+1:

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hi again Dave,

Is there a way I can visualize what I’m doing and if I am correct or not? I tried the scope connected to the CV1 output of sequencer but it is tricky to observe whether I really have the lengths I want or not because I can’t seem to find the period in which my whole sequence freezes in on screen. And even then it is an unexpected result.

I’m also at loss how to keep an idea of “master” tempo, the tempo of the song that does not change regardless what clock division I give to each individual step.

This is the setup I’m trying right now, just for simple visualizing. In my reasoning, the “master” tempo is the one of the built-in clock of the first sequencer, and my note ratio is given by the LFO’s modulation. I also believe the LFO main knob should be set at the same frequency as my master tempo (2Hz=120bpm).

So as said the first sequencer commands my ratios, it has 2 steps: -1V and 1V to half and double my tempo as Omri explained.

Second sequencer has 2 steps: random voltages but I chose them negative and positive so I can see the change easily.

But it show inconsistency for a reason I can’t find. I have a rather hilly output while it should be one long up and one short down. What am I missing? Is it because I actually didn’t need that LFO in the middle? Getting desperate here because it is so simple and yet I can’t predict its behaviour. Thanks…

I don’t see how that design can possibly work. If you want a sequencer to modify the tempo, then it must modify its own clock, not that of another sequencer. Your design will not work properly whenever you speed up or slow down:

  • If you slow down (half speed), then the master will move on to the next step before the subordinate has completed its cycle.
  • If you double the speed, then the subordinate will always play two notes before the master can move to the next step and establish a new tempo.

You also have an issue that your master clock and subordinate clock will almost surely be out of phase. Assuming other problems are resolved, you would need to reset the subordinate clock whenever the master starts or resets.

Regarding my design from my first post - I think I threw you off. My technique is all about modifying the width of each gate, but at a constant frequency or tempo. So rather than talk about 1/8 notes, 1/4 notes etc., it is better to think of it as playing some notes as staccato, some as marcato, some as legato, and some as slurred. In order to get slurred notes, a slew limiter is needed because the VCV LFO cannot do 100% pulse width.

Say each beat represents a 1/4 note. If you set the pulse width to say 25%, then that might be considered a staccato 1/4 note. You could also say it is a 1/16 note, but then it would always be followed by a dotted 1/8 rest. (unless you implement ratchetting as Auret demonstrated)

I would say 50% PW could be marcato, and 99% legato.

If you need slurred, then you need to add a slew limiter (low pass filter can work), and then 99% would be slurred because the slew would prevent the 1% drop from falling low enough to allow a new attack on the next beat. Legato would then be something like 90%.

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