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AngusHastie
Joined: Aug 04, 2004 Posts: 136 Location: London, England
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G2 patch files: 15
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Posted: Wed Dec 14, 2005 8:18 am Post subject:
Skewing the output of an LFO |
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I'm using an LFO hooked up to the AM input of a volume env to fade a sound in and out, but I want to skew the LFO output so that it's off more than on. What's the best way of doing this? I've been messing around with mod amount modules etc. but they never seem to behave quite how I expect them to...
Cheers,
Angus |
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blue hell
Site Admin
Joined: Apr 03, 2004 Posts: 24079 Location: The Netherlands, Enschede
Audio files: 278
G2 patch files: 320
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Posted: Wed Dec 14, 2005 11:49 am Post subject:
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Maybe I got it wrong, but sounds more like you'd want to alter the shape of the LFO. If so, using a shape LFO might be the way to go. _________________ Jan
also .. could someone please turn down the thermostat a bit.
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ian-s
Joined: Apr 01, 2004 Posts: 2669 Location: Auckland, New Zealand
Audio files: 42
G2 patch files: 626
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Posted: Wed Dec 14, 2005 12:45 pm Post subject:
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Mix the lfo (bipolar) with a fixed level and pass through a diode module, the higher the bias, the more 'on' time.
Use a square wave (pos) lfo triggering a envelope through an inverter (gate on during off cycle), FM the lfo with a variable amount of its own output (pre-inverter). The rate is slowed during the on time. |
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AngusHastie
Joined: Aug 04, 2004 Posts: 136 Location: London, England
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G2 patch files: 15
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ian-s
Joined: Apr 01, 2004 Posts: 2669 Location: Auckland, New Zealand
Audio files: 42
G2 patch files: 626
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Posted: Thu Dec 15, 2005 11:20 am Post subject:
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AngusHastie wrote: | G2ian - What's a diode module? |
Sorry, my bad.
Its called a rect (short for rectifier) in the shaper group, it has a diode symbol on it.
The rect module can chop off the negative going part of the lfo wave so your idea with the leveladd will work. Applying neg control signals to the mult (vca) still lets signal through, its just an inverted signal. |
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AngusHastie
Joined: Aug 04, 2004 Posts: 136 Location: London, England
Audio files: 2
G2 patch files: 15
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Posted: Sat Dec 17, 2005 4:24 am Post subject:
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g2ian wrote: | Applying neg control signals to the mult (vca) still lets signal through, its just an inverted signal. |
How does that work then? I thought a bipolar LFO signal oscillated between +64 and -63 and that if you sent this signal through a level add module set to a negative value, it would just subtract this value from the range...? Obviously I'm wrong but I'd lke to know why! |
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blue hell
Site Admin
Joined: Apr 03, 2004 Posts: 24079 Location: The Netherlands, Enschede
Audio files: 278
G2 patch files: 320
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Posted: Sat Dec 17, 2005 6:40 am Post subject:
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AngusHastie wrote: |
How does that work then? |
You seem to mix up multiplication and addition.
The VCA, or multiplier, multiplies it's input signals. When you multiply a positive siganl with a negative one you'll get a negative output signal. But remember 64 times 64 equals 64 on the NM synths.
The adition thing that you desecribed is performed by mixer modules.
The LFO output goes down to -64 BTW, not -63. _________________ Jan
also .. could someone please turn down the thermostat a bit.
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AngusHastie
Joined: Aug 04, 2004 Posts: 136 Location: London, England
Audio files: 2
G2 patch files: 15
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Posted: Sun Dec 18, 2005 6:38 am Post subject:
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So what does the LevAdd module do then? I thought it just added or subtracted a fixed amount to a signal, same as taking a mixer and sending the LFO to one input and a constant value to another input... |
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ian-s
Joined: Apr 01, 2004 Posts: 2669 Location: Auckland, New Zealand
Audio files: 42
G2 patch files: 626
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blue hell
Site Admin
Joined: Apr 03, 2004 Posts: 24079 Location: The Netherlands, Enschede
Audio files: 278
G2 patch files: 320
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Posted: Sun Dec 18, 2005 3:11 pm Post subject:
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I'm sorry for the confusion, I didn't read well. _________________ Jan
also .. could someone please turn down the thermostat a bit.
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dasz
Joined: Oct 16, 2004 Posts: 1644 Location: victoria, canada
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Posted: Sun Dec 18, 2005 3:12 pm Post subject:
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Hey AngusHastie,
I use a control sequencer to create my own shapers .. I feed the input (once passed through a levelconvert module) of the source into a perfectly diagonal control sequencer (step 0 = 0, step 126 = 127). The control input is the soud source. I use a smoother after the sequencer (usually a bit of glide or LPF), now I had really alter the behavior of my shaper.
/Dasz |
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AngusHastie
Joined: Aug 04, 2004 Posts: 136 Location: London, England
Audio files: 2
G2 patch files: 15
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Posted: Mon Dec 19, 2005 3:17 am Post subject:
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dasz wrote: | I use a smoother after the sequencer (usually a bit of glide or LPF)
/Dasz |
Nice tip - thanks. Sorry for my endless questions but how does a LPF affect a control signal? Does it just chop off the high bits?
G2ian - thanks for the patch - will check it out as soon as I get back to my synth.
Angus |
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