DIY Arpeggiator Building Block

[Tim Kleinert]

I isolated the keyboard-scanning/voice-assigning algorithm from my DIY arpeggiators (found here and here) and present it as a building block, so folks can go on and finally build customized arpeggiators with their own desired specifications.

The inputs and outputs of the patch are highlighted and explained with name tab modules. I also included a simple small demonstrational application example (sweeping the played keys with an LFO), showing you how to use it.

There now are almost limitless possibilities, as the played keys can be simply accessed by any control signal (snapped to integer key numbers, pay attention to this ). Sweep the keys with envelopes, random generators, sequencers, the modwheel, envelope followers as you holler into a microphone , other weird stuff, whatever...

Hope you have as much fun using this as I had designing it.

cheers,
tim

Tech talk for the geeks: The core of the patch is a keyboard-scanning routine residing in the FX area. This pipes the MIDI key number it wants to know the status of to the voice area via interslot bus. If the keyboard note value of a voice matches this key number, and it's keyboard gate is on, this voice is considered "active" and it gets a number assigned to it (also via interslot) from another counter also residing in the FX area, which is in charge of counting the played keys. This counter will then advance one step. The result is that all the voices containing played keys are numbered consecutively from lowest to highest played note (or vice versa if you scan from top to bottom), and the total number of played notes is known as well. Now you can trigger those voices anyway you want, by sending the voice number you want to trigger and a keyboard velocity value via the two remaining interslot busses. Done.
There even is a way to trigger more than one voice at a time, by encoding the corresponding gate statuses into one signal via an AD stage, and decoding them in the VA with the note number acting as the mux module pointer. See my 8-voice polyphonic arpeggiator for how this is done. However, you can't have individual keyboard velocities as well. (OK, you could mux those via audiorate counters and demux them, but things are slowly getting out of hand here... )

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DIYArpeggi8BB_TK.pch2
Description:	Building block which let's you design customized arpeggiators.	Download (listen)
Filename:	DIYArpeggi8BB_TK.pch2
Filesize:	3.35 KB
Downloaded:	1883 Time(s)

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[Wan]

Hey Tim,

You are again pushing the borders of what the G2 can do, i think it is brilliant what you are designing and very admirable that you share it with all of us.

Thank you very much

I'm going to delve into this when i get some hands-on time with my G2X.

Grtz Wan