Frequency Divider

Feedback & Suggestions
#1

It would be great to have a frequency divider in the style of The Count Modula Voltage Controlled Frequency Divider.

I am currently working on a synth in the style of the Subharmonicon. I am using Omri Cohen’s creation for VCV Rack that he posted on Patchstorage and YouTube. Between myself and another miRack enthusiast, we have two different working versions.

The current problem is that the suboscillators do not automatically track their respective main oscillators. It has to be done by hand.

I am trying to figure out a way using some other modules and feel I might have something that works soon. However, I have been told that Squinky Labs already has a module that also provides a suboscillator but it is for VCV Rack. It would be great if that could be ported to miRack.

Here is one working version for miRack:

Subharmonicon Emulation
#2

Hi @playinmyblues,
Is it audio frequency division or clock frequency/rate division ?
Both are easy to do… to divide audio frequency use the octave dial… and to divide clock use a clock divider.

I’ve not seen Omri’s video about the subharmonicon, maybe I should check it out.

edit - the SWITCH88 is sending pitch from BOTH quantisers to some oscillators and only one quantizer to the SUB oscillators.
All oscillators need to be tracked from the same source really . ie - a (one) sequencer or a keyboard controller or an external midi keyboard via the MIDI input module.

#3

Hey @playinmyblues, I’ve just watched Omri’s video about the subharmonicon, very interesting… The CountModular freq div looks very useful as it divides clock as well as audio… there are ways around that. Also the BUS ROUTE module, is very handy but I’m sure there are ways around that also…
I’m fairly confident the subharmonicon can be built in miRack even though there are some key modules unavailable…
I’ll take a look at your patch, and have a go myself.
Cheers
runcell

#4

Here is the other version of the Subharmonicon type synth:

Some ideas were used between the two versions but they turned out quite differently. I think this version, by the other builder, has a smoother sound.

#5

It will be great to have another set of eyes and ears looking at this situation. I appreciate any help you can give.

We did fairly well in figuring out how to get around clock division, which while using a different module, I think works more or less the same.

RGATE is the module used for both clock division and frequency division. Clock division requires not further modules to make that specific part work.

The other builder worked out proper accounting for multiple clock signals using an Or logic module. We used the MUTE 8 module twice to be able to turn individual clock signals on and off.

Aside from adding some extra features, we managed to replicate all the functions of Omri Cohen’s version except for the automatic tracking of the subs with the main oscs.

VCV Rack has the Count Modula VC Freq Div II. That module allows for both an input audio signal and a CV signal to change the output according to the division. It is those two things together that allow the subs to track the main oscs. I cannot figure out how to do that in miRack while still allowing for both the main oscs and the subs to receive different values from the sequencers.

It is quite possible I am missing something simple as I am still fairly new to synths in general. I have about 2 - 3 years of playing synths.

#6

I got my first synth in 91 or 92 (Roland sh101 for £100) and I’ve been using them every day since…love em’.
There are lots of modules to choose from, some of which may be perfect for this, that I don’t know about or just forgotten about or not even used… but I’ve got it working. Now I just need to connect up the filter and envelope sections.
The Rgate is almost perfect, because the gate length can be shortened to make triggers therefore the octatrig is not needed… .And the clock frequency/rate can be controlled with a tact slide controller. I say almost perfect because Rgate only does divisions/multiplications in 1,2,4,8, etc… no 3’s, 5’s, 7’s, etc.
I will post it onto patchstorage once I have the filter and envelope sections in place.

runcell

#7

We are using the Beface EvenVCO for the main oscillators and the oscillators for the subs to track the main oscillators. These modules and the BOGAUDIO VCO’s would be perfect for this use if there was a CV input to change the range - the large knob on the module. That would allow the main VCO’s to be tracked by one CV and still receive CV into the V/Oct jack.

I wonder if there is anything in miRack that is like that.

#8

@Runcell, Squinky Labs EV3 might work. Three oscs in one module that track when you change knob 1. Knobs 2 and three can change the octave (I think) and changing knob 1 still has changes in the other two knobs.

#9

Why, oh why, is there no separate knob for the octave on VCO’s? Such a simple thing that would allow me to do what I am trying to do!

#10

I’m using 6 BEFACO oscillators so that each (main) oscillator, so to speak, has the 2 subs… they’re all trackable from either 4 step sequencer.
I tried the using just 2 BEFACO oscillators and the pitch shifter from BIDOO on the split outs but thought it sounded better using seperate OSC for each (subs).
The BEFACO oscillators have an input for octave, by using a fixed voltage source, a switch and a big button… 1 volt per octave, so +1 volt into the octave input = +12 semitones or 1 octave (+8ve).
Alternatively there is STACK from BOG AUDIO, plug pitch CV into STACK first and then into the oscillators 1v/oct input, then can use the octave dial on STACK.

#11

Hey @playinmyblues, I’ve posted a MiRack version of the Subharmonicon onto patchstorage… Let me know what you think.
I’ve used 8 VCA’s instead of a MUTE8 because you can see if a signal is passing thru or not, with the green flashes. The OCTATRIG is not needed because the Rgate, gate length has been shortened to make triggers.
This version is different from Omri’s (although same results) in that I’ve added some of the front panel controls, like the octave (big) button will transpose up or down 3 octaves, filter dial (as a tact-1 slide cntrlr), resonance dial (tact slider again), filter env - attack & decay dials (x2 tact sliders)… etc etc… it loosely resembles the front panel layout.
ALSO… MiRack does not have the BUS ROUTE (logic) module which makes things look a little different compared to Omri’s patch… I’ve had to use 2 OR logic modules and switches.

all the best

runcell

#12

Thank you. I was going to ask about your version so I can see how you are patching things. I will have a look.

#13

I am the other builder that @playinmyblues mentions.

I have to say your version is wonderful and very playable. Lots of things to study and learn from ::slight_smile:

Fwiw, I did load my version last week in patchstorage: https://patchstorage.com/subharmonicon-omri-cohen-v1-0/

Cheers
sowari

#14

Hi @sowarimodular, thanks yes very playable…each time I have a go with it I find something very usable…and each time different.
It took a bit of head scratching to get round the BUS ROUTE module that Omri uses… and it would be nice to have something similar to count modular freq div in miRack, if we haven’t already.
I will take a look at your version and you can always adapt it and copy parts my patch if you want to build your own up.

Thanks @playinmyblues for bringing this up, I now have something to play with…for a bit :v:

runcell

1 Like
#15

Hey @sowarimodular, just been playing on your version… all is good up to the oscillator section… BUt… when I plugged from SWITCH88 outs to the TIDAL MODULATOR’s 1v/oct inputs it all came together nice and definitely useable. Not sure you need the TIDAL MODULATORS in there, but it works.

cheers

runcell

#16

Hi @Runcell, you have a great layout and it makes it looks like fun to play.

I was looking for the frequency division sections. Are you getting frequency division by using the octave range on EvenVCO or is there another section I am missing?

#17

Thanks man :+1:. Yes getting divisions from octave dial on the extra oscillators.
The frequency division (count modula) is only necessary if using only one oscillator (for each oscillator section)… what Omri does is take a split from one oscillator, half’s the frequency with count mod (which is 1 octave lower) and labels it OSC 1 sub 1… he then half’s the frequency again with another split & count mod so that sub 2 (osc1+2) is now 2 octaves below.
What I’ve done is use 3 oscillators for OSC 1 (the osc plus the 2 subs) and 3 for OSC 2 so there is no need to split then divide. Sub OSC 1 is one octave below and Sub OSC 2 is 2 octaves below. This is because we do not have count modula audio/clock freq divider for MiRack… I tried a pitch shifter from bidoo, but preferred the sound of how it is now.
Hope that helps

runcell

#18

Thanks for the explanation. I think I had just gone about it in a way that was sticking with the Omri Cohen’s version. But is really more arbitrary.

I really like the big buttons and Tact-1 sliders, which are great for the iPad. The sound from yours is much smoother than mine.

It is great to see other modules used in the process.

sowari’s version is also a lot smoother and has some interesting controls for reverb and delay. And then there is mine, which has a little more grit in the sound, if you like that sort of thing. It also allows for more control over the shape of the sawtooth wave, changing from descending to ascending and points in between.

I think the reason I used a modulation generator was it allowed me to get a descending sawtooth wave while EvenVCO only has ascending. The Moog Subharmonicon has the descending sawtooth.

#19

No problem :+1:. I followed Omri’s way, except for the Octatrig (because Rgate length can be shortened to triggers) and the oscillator section… Oscillator 1 is actually 3 single oscillators instead of 1 oscillator spilt twice. And oscillator 2 is the same.
The big buttons and Tact slide controllers are perfect for iPad…
To flip a saw wave or any wave, you only need an inverter or an attenuverter, like the one from BEFACO, just plug the saw wave thru this and turn the white dial (fully) anti clock wise… and check it on a scope to see.

runcell

#20

Thanks for the tip on the sawtooth wave inversion.

I think I would still like to see the ability to change the octave selection with any VCO. I would like to be able to use one CV into a multi to change a bunch at one time.