LFOs for Controller Transforming

B

Bakerman

Axe-Master
Here are some techniques for extra modifier options, compared to one source assigned directly to a parameter.

By choosing a stopped LFO as source instead, and the actual controller you want to use as source for LFO duty %, the LFO output can travel the full modifier range instantly or over a small zone within the controller's range.

1. Assign LFO 1B or 2B to the target parameter like wah/pitch control, mix, rate, etc.
2. Go to the LFO's page, select trapezoid waveform and assign a run modifier to stop it. Use any source and put start/mid/end at 0/0/0.
3. Set Output B Phase to 2.8 degrees, make sure depth is 100%.
4. Assign the control source you want to use (like a pedal's External) to LFO Duty %.

Now moving the pedal from 0% to about 3% will make the LFO go from 100% to 0%. You can adjust the duty modifier's offset/scale and mid/end to make the change occur over any portion of the controller range. Increasing B Phase can make it easier to target larger ranges. The change (LFO output moving 100-0%) that occurred over 1-4% duty will shift/expand to 32-99% as you move B Phase toward 88%, which is the maximum value that still produces the full LFO output range.

If you use a square LFO with B Phase at 180 degrees, duty % becomes a min/max toggle with 50% as the switch point.

These presets use the 2 waveforms on a whammy block with External 1 as the controller.

http://dl.dropbox.com/u/28651/axefx/LFO ctrl trapezoid.syx

http://dl.dropbox.com/u/28651/axefx/LFO ctrl square.syx

Not intended to sound amazing, just easy to hear how the controller movement translates to some parameter change. More interesting examples might use things like pitch or ADSR as source, and other target parameters.

A few variations:

Get the LFO movement mapped to the full pedal range then assign an IA to toggle LFO depth between 100% and something else like 50%. Now you can choose between a larger or narrower sweep with a fixed center value.

Assign envelope to LFO Depth. A pedal/IA on duty % can control the direction & depth of the envelope's modulation.

Assign an IA to duty, pedal to LFO depth. Use LFO to control whammy in +/- 1 or +/- 2 octave mode. The IA will change the pedal's action between down-only and up-only.
 
One-cycle LFO sweeps:

An LFO can be run once through part/all of a cycle by assigning the LFO as its own run source and using something else as a depth modifier. The run modifier needs to be set up in a way that allows a brief depth change to bring the dot (representing stopped LFO position) from below the off threshold (45%) to above the on threshold (55%). Presets below use triangle LFOs, which won't be shown correctly in Axe-Edit.

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Here LFO 1A will sweep a synth filter. Engage synth & toggle External 2 to hear it. http://dl.dropbox.com/u/28651/axefx/LFO 1 cycle Ext 2.syx

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Slow crossfade: http://dl.dropbox.com/u/28651/axefx/LFO A-B fade Ext2.syx

Start with External 2 at 0%. Set up 2 chains in rows 2 & 3 before the mixer's column. Synths are there as an example; engage to hear them or remove. Switching External 2 to 100% will cause a 20-second fade from row 2 to row 3. Increase LFO 1 rate for a faster fade. Returning External 2 to 0% will switch back to row 2 instantly. The filter bypass modifiers use damping for a delayed switch from row 2 to the mixer output. No damping would cause a quick mixer fade in the opposite direction to be audible at the start of the LFO motion.

To always have the crossfade available immediately after switching to the preset, the LFO has to be stopped in the previous preset. If not, it will usually be running at this one unless it was at 0 degrees by chance. Row 2 will be sounding as expected, but you have to wait for the LFO to stop (anywhere from 0 to 20 seconds) before it can be run again. Otherwise you'd switch and hear the crossfade in progress.

Volume blocks also work for fades. This makes it easier to have separate post-fade effects like sustaining delay/reverb of the sound that fades out. Here are fade-out (Vol/Pan 1) and fade-in (Vol/Pan 2) blocks with LFO 1 & Ext. 2 working as in the last preset. http://dl.dropbox.com/u/28651/axefx/LFO A-B fade Vol blocks.syx
 
tried to download the patches from your last post and either the link is broken, or there is another problem...they wouldn't download...

i'm interested in doing some very long crossfades between two chains, so these would be helpful to me and i can't quite grasp what you're doing from your description...
 
Nice. I take this as another measure of interest in the SWITCH controller that's discussed on the wish list. I brought that to Cliff's attention, but we haven't had time to discuss yet.
 
Admin M@ said:
Nice. I take this as another measure of interest in the SWITCH controller that's discussed on the wish list. I brought that to Cliff's attention, but we haven't had time to discuss yet.
Click to expand...

whoa...i missed this.tried a search, but no joy....linky please?
 
Here they are as attachments. If you're wondering, it's possible to do a fade back to sound A too instead of an instant switch. I'm still trying to figure out what would use the fewest modifiers, current idea needs 12.
 

Attachments

  • LFO 1 cycle Ext 2.syx
    2 KB · Views: 6
  • LFO A-B fade Ext2.syx
    2 KB · Views: 6
  • LFO A-B fade Vol blocks.syx
    2 KB · Views: 6
Do you think this works on a II also ? Must admit that after a working day it's a bit hard to get it into the brains but I think I start to see the light -> this permits to launch an LFO just for a single cycle "on demand (CC-controler)" doesn't it ? (and much more also but...)
 
Everything so far should work about the same on the II. Yes, one cycle then stopping is possible and used in the sweep/crossfade examples.
 
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