A quick scour of the Digitakt forums didn’t yield any results so I figured I’d share the technique in a new thread.
Since I can’t seem to find keyboard tracking on the DT, specifically for the filter cutoff, I decided to set it up (or a reasonable approximation of it) using an LFO. I’ve used the following settings:
SPD: 63.99
MULT: 2k
FADE: X
DEST: FILT FREQ
WAVE: RMP
MODE: HALF
DEP: Used for amount of tracking you want.
Seems to work well enough to track the filter cutoff for my needs.
In the past to get around this I’ll set up a Kit with 8 voices of the same sound. You are then free to tune each filter (and each lfo)
Setting up polyphonic kits like this can sound luuuushhh.
The technique you’ve made is interesting, moving the resonance peak across a spectrum of sound fast enough to amplify any given fundamental frequency in the range.
If you didn’t want to sacrifice 8 voices, you could use the 8 midi tracks with midi loopback to hold settings for just one voice.
In effect you would have a keyboard on the bottom 8 midi buttons that you could tune to a scale!
I think I might spend some time and do this today.
I don’t hear a difference between this and just changing the filter frequency directly?
I also am trying this and am not finding it tracks the filter to what key I’m playing, it’s just another way of opening and closing the filter. I’m trying it with noise and hearing no difference in filter setting as I play at extreme ends of the keyboard
Can’t remember how I came to the conclusion that it was working but my old man ears probably thought it did at the time. 
I do recall trying to solution for the lack of keyboard tracking on the DT though. Reading the above instructions, I see there’s no way to assign for the note number to affect any parameter at all. If there were, it’d be called ‘keyboard tracking’ o__o
File this under over-excited durp
Sweeping the filter quickly through the full spectrum will be more noticeable on the harmonic series of the specific sound. It could be that you just did a localized sweep in the octave you were playing in and it sounded like the filter was tracking.
Y’all should try setting up a kit the way I describe above. It’s very nice