Polyphonic MIDI Recorder/Looper

[Tim Kleinert]

Hi,

I always wanted to have a looper for the G2. But since the audio delay lines are to short for a reasonable loop length and I would be looping keyboard performance anyway, I thought it maybe would be possible to design a looper/recorder for MIDI data. Which is what this patch does.

It's based on a new patching technique which transforms an audio delay line into virtual RAM memory, where values can be written into or read from.

The patch is intended to drive other G2 slots or external MIDI gear. It is capable of recording exactly 60 seconds of MIDI performance. The control circuit is in the FX area and each voice acts as a "voice recorder", so the polyphony count determines how many voices you can actually play and record. I kept everything as simple as possible, so a "recorder voice" is below 16.6%. I added stuff to make the patch able to deal with voice-stealing. Velocity is recorded too, but not modwheel and other performance controllers.This can be added in future versions.

The controls:
RECORD Arm: "Arms" the recorder, makes it ready for recording. You now can play on the keyboard and the notes will be put through to the destination playback device (eg. patch in another slot). The patch now waits until you press...
RECORD Start: Starts the recording process. From now on everything you play will be recorded. (If you override the 60 seconds limit, the patch will simply shut off and you will have to start anew.)
RECORD Stop: Stops the recording. The circuit shuts off back into playback mode, playing back your performance. (Playing further notes on the keyboard has no effect anymore.) You can now jam over it with something else (a patch in another slot, whatever...)
MIDI CONTROL Channel: destination MIDI channel

This patch uses 2 interslot busses.

Due to the design of the patch, the keyboard status is updated 40 times a second, which means that the playing response isn't super-crisp. It's OK though.

This is the first patch using this new technique and deliberately has no bells and whistles to keep things as economical as possible. (It could be economised even more by leaving out the recording of keyboard velocity data, but I considered that to be a bit too unmusical.) So it's an one trick pony, but a trick you've never seen from your G2.

It is perfectly possible to add MIDI clock-synchronised looping, multi-channel realtime MIDI controller recording/automation and other elaborations, making it a full-featured MIDI-looper. I will try to add this in the future as time permits.

cheers & have fun
tim

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60sMIDILooper_TK.pch2
Description:	Polyphonic MIDI recorder/looper with 60 seconds of recording time	Download
Filename:	60sMIDILooper_TK.pch2
Filesize:	2.69 KB
Downloaded:	2300 Time(s)

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[dasz]

a big thank you, Tim! I tip my hat to you, sir.
/Dasz

[Roland Kuit]

ofcoarse! a genius idea after your audio sampling techniques. thanks!!!!!!

[dorremifasol]

I've not tried it yet but with the description I'm already excited

I'll try it tonight, thanks!!

[Moody33]

I've made a sync midi looper a long time ago. It gives me 2 more voices than yours (24 versus 22 on my unexpanded G2) . It is sync to clock, so you can speed up and down what you have record. Still need improvements cause it give voice stealing and need more controls. I haven't got the time to work on it, but you can also loop red signals with. I hope it will give you some ideas for crazy patches !

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SyncMidiLooper.pch2
Description:	really basic midi sync looper.	Download
Filename:	SyncMidiLooper.pch2
Filesize:	1.21 KB
Downloaded:	1953 Time(s)

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[Electromagnetic Wave]