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WIGGLING 'LITE' IN GUEST MODE

Fun with the Serge Divide by N Comparator
MUFF WIGGLER Forum Index -> Buchla, EMS & Serge  
Author Fun with the Serge Divide by N Comparator
paradigmshift
At pickleinn's urging I tracked down an old discussion about the NCOM which I took part in during the "golden era" of the Serge Yahoo list. Ya know, back in the days when John Duval still owned his Fist of God! (No disrespect intended to those who inherited a knuckle or pinky.) I hope this answers a question or two and spurs further exploration.

"I have been trying to grok the Divide by N for quite some time but still don't think I have it down. It seems to be a really quirky and very useful module...if I just understood it better. Here is some of what I noticed it can do...

CV PULSE MOD - Put in a sine wave at either of the bottom two blue jacks, set the -/+ at around 12 o clock to find the sweet spot and feed a slow smooth CV / LFO into the other blue jack. Take the output of the middle red jack as an audio out (but it's RED?) and you have a nice CV controlled pulse mod. If you don't put a CV into one of the inputs you can get a pretty nice variable pulse wave and use the +/- knob to set the duty cycle (useful for those that only have PCO's)

Speed up the LFO to audio range and you get some really strange ringmod/heterodyne timbres. Tres' cool. Noticed the changing the audio input to Tri or Saw does not affect the basic sound too much: still a pulse wave. You may need to attenuate the CV signal and tweak the +/- knob to find the 50% Square and limit the swing of the pulse mod so it does not go past 0 or 100%.

AUDIO FREQ DIVIDER: With the same patch (with or without the pulse mod CV), take the top red jack as the audio out. Set the Osc freq pretty high and turn the top 1-31 knob. You get a stepped odd scale of discrete descending pitches as you turn the knob clockwise. I noticed that there is a fairly significant volume "thip" as you divide the pitch down that sounds a bit like a quick saw-like transient. However, turning the knob counter clockwise and going north with the pitch you get an INVERTED saw like 'thip" - the opposite of going down. Putting any kind of slow smooth or stepped CV into the middle VC in make the pitch jump based on the type/shape of the CV. A sample and hold like, stepped signal gives this aleatoric jumping pitch scale and a smooth random signal swings the pitches in a, well smooth way through the division. It usually helps to use some attenuation on the CV IN to control the max deviation as all the way down the audio cuts out.

There is also a really noticeable timbral change that comes from the top jack audio...very much like a thin pulse wave no matter what the input (sine, saw, tri). It is also kind of "dirty" sounding and at high mod speeds you also get some sideband like timbres though not as clean as the ones from the pulse mod.

VC PULSE DIVIDER: Like the audio freq divider you can send in a stream of triggers and use the VC divide (knob for manual, cv in for modulated) to define how many input pulses it needs to "see" before it outputs a pulse from the top red OUT jack.

COMPARATOR/PULSE EXTRACTOR (+ PULSE DIVIDE): Plug two different random CV signals into the two bottom blue jacks. Take the output from the lower red jack and use it as a clock for a seq or envelope. There is some formula for when a trigger pulse will be generated (when the +in is greater than the - in and if the tide is high of the second full moon of the third month...or something like that).

You can take the top red Out and use that to trigger some other function and again, either manually control/divide how many input pulses need to occur before an output pulse is generated depending on the setting of the upper knob and the CV signal going in the blue VC IN jack."

> I can't tell what the red STEP OUT jack does - it seems to not only provide a divided signal out (in the audio range) that is less "thin" (though still pulse sounding), but it also seems to have a volume change associated with each step; volume getting softer the higher the pitch.

This is actually what provoked me to focus on the /N-COMP, because I realized I'd never used the STEP OUT jack before! After reviewing the Serge catalog and tweaking for a while I found that when plugged into a 1v/oct input of a VCO the STEP OUT produces a series of rising pitches from the VCO. Each "step" up is a whole tone, with the number of steps determined by the upper pot and the speed of the staircase progression determined by the rate of the pulse generated from the comparator in the lower section. Through most of my experimentation Monday and tonight, I used 1/2 a DTG as voltage source into the IN+. Both voltage and gate outs of the DTG worked well. Note that if the lower section pot is set so that no pulse is generated at the lower red OUT, then you won't get output from the STEP OUT either.

I was able to generate from 0 (constant pitch) to 31 rising steps, and with at least 2 pitches the cycle repeats itself. I also tried patching the STEP OUT to other destinations, such as filter cutoff, VCA amplitude, Phasers, Wave Multipliers, etc, and the results are just as pleasing! Patching the STEP OUT into the bottom section of an ACPR let me invert the staircase to generate falling-step series, which sounded particularly good controlling VCAs, and this effect produced even more "natural" decays when the ACPR out was lagged slightly on its way to the VCA.

> Speed up the LFO to audio range and you get some really strange ringmod/heterodyne timbres. Tres' cool. Noticed that changing the audio input to Tri or Saw does not affect the basic sound too much: still a pulse wave.

I found that changing the audio-rate "LFO" waveshape produced very interesting klang tones. Try using an NTO variable waveform out as the "LFO" and modulate the pitch and waveshape with sequencer rows or other CV sources. (If you have a Miniwave, this is another great source for this purpose.)

One patch I liked a lot:

* Patch a VCO SAW OUT to one input of an audio mixer.
* Patch the /N-COMP top red OUT / to the mixer's second input.
* Patch STEP OUT to the VCO's 1V/OCT IN.
* Patch a DTG/DSG to oscillate in the audio range with its OUT or GATE OUT patched to the IN+ on the bottom section of the /N-COMP.
* Set /N-COMP top pot far left ("1") and use the DTG/DSG rise/fall pots to tune the /N-COMP OUT to some harmonic of the VCO's pitch.

You should then be able to turn the top /N-COMP pot left and get some nice timbres. I found these to be much richer tones than I could achieve simply by running the same VCO SAW into one of the bottom inputs (IN+/IN-) of the /N-COMP and taking the top OUT. I later expanded on this by running one sequence row to control the VCO's pitch and a second sequence row to the /N-COMP's VC IN.

A couple of general observations:

1) The /N-COMP's upper VC In "subtracts" from the pot setting, so for instance to vary the number of N from a TKB you should set the /N-COMP's upper pot to the far right (-31) and the TKB's pot settings should allow you to dial in a range from 0 steps at far left to 31 steps at far right.

2) I found the Quadrature Osc to be a great PWM source for the COMP section since its built-in VCA lets you easily dial in the maximum modulation range without exceeding the 0% or 100% duty cycle."

I know this is a lot to take in but like many modules on the Serge this one is extremely deep. Incredible bang when you consider the narrow space it takes up!

Happy patching,
Chris
J3RK
Thanks for posting this! I'll keep it in mind for when I'm finally able to grab the Dual VCO M-odule.
confusional
Redacted.
zthee
paradigmshift wrote:

> I can't tell what the red STEP OUT jack does - it seems to not only provide a divided signal out (in the audio range) that is less "thin" (though still pulse sounding), but it also seems to have a volume change associated with each step; volume getting softer the higher the pitch.


If you check the 1982 catalog it says the step out is a staircase corresponding to the number of divided steps. And it will increase with whole tone steps if plugged into a 1V/oct input. 1V/6 = 0.166..V - So if you set the divide knob to 1 - the pulse from the step out will be 0.166..V high. This will sound very low. If you set the divide knob to 9 you'll get a staircase that steps from 0, to 1.5V. And so on - so 31 x 0.166.. = 5.166..V
GeneralBigBag
Step out makes a great source for VC cross-fades - I have the Gator, and set up two different rhythms patched into the mixer, and cross fade between the two using step out.

It's also a pretty weird oscillator if you drive it fast enough....
pickleinn
applause
Thanks for the post! I love these kind of posts that describe patches for what seems like a very simple module.
caetanosfur
I've been wondering: what kinds of things can the NCOM do with samples? Can it reliably derive related pitches from samples? And the following (from the R*S Eurorack manual) makes me wonder about other kinds of uses with samples: "For sub-audio frequencies. the divider acts like a counter. Outputting a pulse only after ‘’N’’ number of input pulses. Input pulses can be fairly random or reqular. This capability is especially powerful for detrmining
tempos and rhythmic patterns when using several sequencers (especlally if the “N” VC input is taken from one of a sequencer’s rows of controls ). ln a more random situation, using a microphone preamp / detector as input, the divider might be set to count how many times a sound of a certain loudness will have occured and be set to trigger an event upon reaching the count. Since the count can be made variable (from 1 to 31), fairly complex and subtle interactions can be generated"
beem
caetanosfur wrote:
I've been wondering: what kinds of things can the NCOM do with samples? Can it reliably derive related pitches from samples?


It behaves like a bitreducer/crusher almost. So yes, but the result is pretty mangled if the sounds have an unclear frequency (if that's understandably explained).

caetanosfur wrote:

And the following (from the R*S Eurorack manual) makes me wonder about other kinds of uses with samples: "For sub-audio frequencies. the divider acts like a counter. Outputting a pulse only after ‘’N’’ number of input pulses. Input pulses can be fairly random or reqular. This capability is especially powerful for detrmining
tempos and rhythmic patterns when using several sequencers (especlally if the “N” VC input is taken from one of a sequencer’s rows of controls ). ln a more random situation, using a microphone preamp / detector as input, the divider might be set to count how many times a sound of a certain loudness will have occured and be set to trigger an event upon reaching the count. Since the count can be made variable (from 1 to 31), fairly complex and subtle interactions can be generated"


What they describe here is more like a clock divider, with cv controllable division. Not really applicable to samples, if not just to get sub rhythms from triggers so to speak.
FatRocky
How this R*S eurorack NCOM compares to the R*S 4x4 Divide and Compare module? hmmm.....
wavecircle
I have the RS NCOMP in my system, as far as I know it's the same as the Euro version, great little module, does so much cool stuff.
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