"Playing" the comb filter using a custom LFO?

Elektron Gear Octatrack
#1

Alright, let’s see if the fancy Elektron peoples can help me out with a crazy idea. The comb filter is dope for making melodic sequences on top of parts that are playing. It’s almost like having a nutty synth on top of any sound. I was thinking of figuring out how to use the LFO designer to play the comb filter in key with a song.

It seems that the comb filter goes from A#0 to A9. If my math serves me (and I hope it does), that means 10 octaves with 12 notes a piece, so 120 total steps. The LFO designer has 256 total positions (-128 to 127). 256/120 means approximately 2.1 steps on the LFO designer for each note jump, yeah? But I’m assuming that’s if you have the LFO depth turned all the way up.

So if I want to be able to play the CF with the LFO in key, I’d have to set all the LFO designer steps to the proper values for each note?

Am I taking crazy pills here, or does anyone think this makes sense? I plan on testing it out, but it seems pretty deep to tackle on my own.

#2

I do it oftenly. Exemple on the “bass” sound, Lfo Designer, HOLD, with randomize speed by random lfo 2.

Used in these :

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#3

What intervals did you figure out per note for the LFO Designer? I started making a spreadsheet with CC values based on the 128 steps of a knob and the 120 notes.

Those bass lines sound dope.

https://docs.google.com/spreadsheets/d/19jtLoDaZfdNz2Q4BBThN3P2KY7dNZev9L2-iTzcC5SU/edit?usp=sharing

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#4

I usually use a minor 7 chord, or a minor pentatonic, or minor scale…

Choose a root note first

minor 7 notes :
0 Base note
3 m3rd
7 Fifth
10 7th
12 Octave
15 m3rd
19 Fith
22 7th
24 Octave

Pro Tip to set the notes by ear : set temporarily to mode TRIG, Speed 0
Set first note
Shift Lfo values with Fn + Arrow keys
Set next note
Shift again, etc…

Set back to a different speed, mode (I use Hold, to trig the lfo only on trigs, trigless).

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Octatrack LFO designer and "fractal" generative melodies
#5

Multiband Comb Filters!

Just recorded what I experimented today :

Same Amen Break loop on 3 tracks, filtered per frequency :

T1 : Filter > Bass drum Comb note D1
T2 : Filter > Snare COMB note D2
T3 : Filter > Hihat / Cymbals COMB note D3

1 bar pattern, modulations with crossfader, some one shots, compressor / delay on Master T8. For comb filters I use same principe as above, Lfo Designer with 4 notes, Hold, speed modulated by crossfader.

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Parallel filtering on OT
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Help me fall in love with my OT before I part with it
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#6

i don’t have an OT anymore but the combfilter was one of my favorite things about it. i always just tuned it by ear (hopefully) and adjusted modulations as i went along.

all these tracks use/abuse the combfilter.

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#7

Interesting! Fast Lfos on Comb pitch?

2 Likes
#8

OK. That’s dope af. Can you share that project file with me so I can dissect it? Damn.

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#9

fast slow etc on everything comb related… it was a fun way to explore and find the sweet spots… often had to walk it back a bit to get it to sit right but loops going around and around while tweaking FX is one of my fav things to do.

btw if you design a custom LFO and make it go really fast then modulate the speed of that LFO w/another LFO all kinds of weird things emerge especially on longer drone type material that’s looping nad all the start/end etc times of the sample are being modulated. it’s sort of a faux granular type sound. i used that technique on the noisy pad type weirdness sounds underneath everything… on that bandcamp release i linked (free download btw)

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#10

I dont understand how you are doing that.
But it is awesome.

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#11

Amazing!

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#12

:thinking:…Yes, but be careful, I used Roswell Alien techniques, you may have trouble with US Army…

Yes, 8 times faster. I use it too for AM/FM (vol/pitch). I also tried fast random lfo on Comb to make noize from incoming audio.
I also modulated Comp pitch slowly, makes really efficient flanger fx. Have to try again fast lfos on it! :wink:
Thanks for precisions.

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#13

Proper tip sharing right there!

4 Likes
#14

I mean, if the radioactive sandwiches we’ve been cooking haven’t gotten us in trouble already… :wink:

Can’t wait to peep the project. I love this idea. Now I just wish there was a way to save LFO designs for other projects!

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