Monophonic random-LFO

[torsig1967]

I wanted to make a monophonic LFO modulating a polyphonic patch - vintage polyphonic synthesizer style that is.

No problem with the usual wave forms and S/H but I found no way to make noise modulation monophonic. There's a nice LFO random generator but that one has no "mono" button.

Any solutions?

[Falk]

Might this work?

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MonoRandomLFO.PNG
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[torsig1967]

[v-un-v]

[Falk]

Hi torsig.

If you clock a S/H high enough, isn't that noise?

Is there something that I am missing?

[torsig1967]

[Falk]

Ok torsig.

This is what you want then. An inverter connected to itself gives the fastest clock that will reliably clock the ClkRndGen module.

Hopefully it is noisy enough for you.

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FastRandomMonoLFO.PNG
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[torsig1967]

Thanks, but what I really was looking for was a monophonic version of the random generator. Maybe it's not right to call that noise. it's not S/H either.

Sounds to me that the closest I get is to use a monophonic S/H and then send that to a smooth module. It has to be manually tuned to the frequency of the S/H though.

[Falk]

Either the glide module or a low pass filter (static ones are not that expensive).

Also try out pressing the Col button on the ClkRndGen module. That makes a large difference as wel.

Off to bed for me ....

[davep]

Well THAT's strange - it looks like the MONO button on the ClockRand module doesn't work! Regardless if the mono buttton is depressed or not, the ClockRand module generates a DIFFERENT random value for each voice, even when it is clocked from a MONO LFO square wave.

But here are a few workarounds. The basic idea is to create a complex control signal by combining & processing a few simple waveforms from LFOs in MONO mode. technically, the signal isn't random, but when you add three LFOs at different rates & levels, and start runnign them through Ring Mods or WaveWrappers (that are in turn modulated by another MONO LFO) it starts to sounds pretty random, yet it retains the MONO behavior across all voices. Try different waveforms & different ways of combining & processing them for different behaviors.

I started using this idea out of necessity when I was making giant sweeping pads with fifteen LFOs and started running out of DSP. I discovered that two slave triangle LFOs at different rates combined in a Control Mixer sounded quite random and used a lot less DSP than the slave random LFO.

BTW, in these examples, the MasterOsc2 is used to provide a single-knob master rate control for the complex LFO signal. If you do this, be sure to turn the KBD tracking OFF or it won't be a MONO signal.

These examples all use three LFOs, but they are combined & processed in different ways to give an idea of the different types of 'behavior' that are possible. For example, the control signal behaves differently depending on whether you simply add the LFOs together with mixers (first example) or if you multiply them together using VCAs (second example) or do something more complex with wavewrappers & ring mods (third example). You can also use things like static shapers and KYBD/VEL scalers to alter the response.

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MonoRandom1.pch
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MonoRandom2.pch
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Filename:	MonoRandom2.pch
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MonoRandom3.pch
Description:		Download
Filename:	MonoRandom3.pch
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[Falk]

Well shame on me for not testing. I just assumed it would work.

Nice to see alternatives davep!

/Falk