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Stereo sample as modulation source.

Stereo sample as modulation source.
« on: May 04, 2019, 09:05:12 AM »
Another question for my upcoming project. I plan to add some low frequency signals in WAV file. Some strange envelopes, quirky shape LFOs. I thing it might be fun to add different signals in two stereo channels. Now: I don't know, what happens, when I will modulate single source destination. Or destination, that might be double, but there is no answer in manual.

Here are questions:

1) What happens, when I modulate single destination, like effect parameter, with stereo sample?

If answer for first question is that they are summed before ANY modulation, next questions are easy to answer by myself.

2) What happens, when I modulate potentially double destination, like filter cutoff (not L nor R using two mod matrix channels, but simple cutoff), resonance or VCA, with stereo sample?

3) What happens, when I modulate stereo sample with stereo sample? Do they modulate each channel respective channels of modulated sample (L -> L and R -> R)?

Thank you for your patience and attention.

Best Regards,
Norman

Re: Stereo sample as modulation source.
« Reply #1 on: May 04, 2019, 10:09:08 AM »
I don't know the answer but now you have me curious.  If you experimentally confirm one answer or another please post your results.  At least one possibility is that it could have entirely independent results on the left and right channel.  After all, the Prophet X is capable of sixteen note polyphony in mono, so why not?

laurentluigi

Re: Stereo sample as modulation source.
« Reply #2 on: May 04, 2019, 12:12:58 PM »
Hello,
I had a little time so I've just tried to modulate stuff with stereo samples....
I've tried to stay simple to understand the exact meaning of the sound....
Inst 1 - level 0-
Osc 1 - level max-
The sample is an envelope.

It's huge....

Assigning stereo sample to Cut off on a simple sawtooth wave....
Ok... It begins.....
But when you make a loop with the sample and modulating the size until granular..... Move the Center Loop...
5 minutes only and you're million miles away reality....!!!!

Only 5 minutes...

Thank You Dave!!!!
Now I going to play thus keyboard with my passport just in case!!!!!!

Bye everybody!!!


With 2 different modulation lines on Filter L/R.... Things begin to be serious.....!!!
« Last Edit: May 04, 2019, 12:15:57 PM by laurentluigi »

Re: Stereo sample as modulation source.
« Reply #3 on: May 04, 2019, 04:20:59 PM »
Oh my!

(...) I had a little time (...)

And to think that I was carrying this idea for over a year since someone mentioned in John Bowen forum that he is using samples to modulate oscillators... More than a year, what could be more, if someone in YT had not demonstrated similar idea for modular samplers. And you had a little time. I need to reevaluate my time schedule.

What did you modulate with that sample? What was the effect? I mean: how does your mod matrix look like? What did you choose as a destination? What - spiritual travel aside - was the outcome? Have you tried to modulate another stereo sample with one sample?

And another question. Since I am looking at SoX and creating my envelopes with a lot of code first in CSV and then converting to wave, you did that in very short time far ahead of me. What tools did you use? Maybe there is some app to hand draw wave file I am not aware of (that would be not surprising as synthesisers are "only" my new hobby)? Nevermind, just found out about Audacity with adequate tutorial. :-) Back to square one. Audacity doesn't allow to draw in that time scale...
« Last Edit: May 04, 2019, 04:57:36 PM by normanion »

Re: Stereo sample as modulation source.
« Reply #4 on: May 04, 2019, 04:46:12 PM »
I don't know the answer but now you have me curious.  If you experimentally confirm one answer or another please post your results.  At least one possibility is that it could have entirely independent results on the left and right channel.  After all, the Prophet X is capable of sixteen note polyphony in mono, so why not?

Will create one consecutive not overlapping envelopes in two channels in one wave file. And another one with overlapping, same looking but inverted envelope. Those two should tell me, what happens and when they are summed. Actually, I will prepare third one with inverted envelope slightly offset, to find, if there is any signal coupling.

Oh, and BTW: I asked guys from Xaoc Devices (there is long weekend because of state holidays here in Poland right now, so they will answer no sooner than Monday) to contribute their envelopes from their module Zadar to this project. Most can be recreated, but I am not sure I have patience to analyse and write few hundreds equations and implement them in code. Although I recognise it could be good exercise in coding.

Re: Stereo sample as modulation source.
« Reply #5 on: May 04, 2019, 07:24:11 PM »
I don't know the answer but now you have me curious.  If you experimentally confirm one answer or another please post your results.  At least one possibility is that it could have entirely independent results on the left and right channel.  After all, the Prophet X is capable of sixteen note polyphony in mono, so why not?

It's 4:20 here, but I finally have my answers. When I used stereo wave file with envelopes, my Prophet X used only left channel for any modulation that I tried.

Now I need to find some convenient way to draw infrasound waves. Using my ad hoc method - Excel, SoX, Audacity (to correct clipping) and text editors - is time consuming.

Re: Stereo sample as modulation source.
« Reply #6 on: May 04, 2019, 07:39:43 PM »
But when you make a loop with the sample and modulating the size until granular..... Move the Center Loop...
5 minutes only and you're million miles away reality....!!!!

Here is my other idea:
1) Make instrument with long line with values from -1 to 1 (or -0.8 to 0.8 to prevent overdriving), like single cycle saw over second or two.
2) Loop this instrument and shorten to shortest cycle possible.
3) Center playback at 0.0 or lowest value - this requires some testing, but we will find out.
4) Set modulation from CV to loop center.
5) Connect Prophet X output to CV jack.
6) Turn modulation amount to desired feedback levels.
7) The longer the loop size, the greater the jitter.

That's my theory. You are acting fast and probably will be next to your unit, when I will be sleeping. I hope results will be good.

Regards,
Norman