Controlling Frequency With Key Tracker Exactly


I would like to control a cutoff frequency of a filter device with a key tracker device in the way that one octave on the key tracker exactly doubles the freqency… I still didn’t get to manage this standard case. Is it possible?

I don’t know if there’s an easier way, but I’m sure the formula device can help (remapping the output of the key tracker device to whatever you need).

AFAIK the formula device is inofficial, so use it at your own risk:

I wonder why this is so difficult.

In the key tracker meta device, there are some curves to select and also range “octave”. But if I select “octave” or “soft”, the key tracker will only send the same value always.

Is my demand realizable with the key tracker device?

This is a bit unspecific. Do you want to double the filter freq linear (rising) or per octave (one step)?

“octave”: the set parameter range spreads from C to B, on each octave.
“soft”__: parameter value is only sent, when you hit a key within the defined key-range
“clamp”_: parameter value is always sent, beyond the key-range with the max/min defined value

There are at least two simple choices to solve your problem (for any target frequencies and constellations):

  1. Use a single key tracker and trigger a LFO containing your target frequencies
  2. Combine multiple key tracker instances (using the “soft” range)

Hope, this helps. :)


I understood him as looking for frequency changes per halftone, like this: f’ = f * 2[sup]1/12[/sup] but I’m just guessing.

I don’t think so. In some other thread he described EQ parameter changes of a hardware synth by changing octaves. But I’m also just guessing. :D Anyway, he should be able to solve this now. :)