GR-55 - epctl Synthy - with MIDI Solutions Event Processor

Started by shawnb, March 29, 2013, 04:04:54 PM

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shawnb

All -

This "Chariots of Fire"-ish sound is yet another wacky experiment from yours truly.  Followup from some old thread here...  I wanted to see how practical it would be to use the E-string as if it were a controller.

In the attached .mp3, strings 1-5 are used for playing notes, and string 6, the low e-string, is a controller.   Many of the frets on the E-string map to a filter cutoff fequency; the rest map to LFO rates.  You'll hear me play a bit then futz with the controller to alter the voices.   

I have the Ctl pedal mapped to Hold, so you can mess with a held chord or note!   

To use the E-string as a controller, this voice requires the use of a MIDI-Solutions Event Processor.  The Event Processor program (attached) simply takes the E-string notes and xlates them as follows to CC values:
  • Low E (note #40) to 12th fret E (note#52) are xlated to CC88 MIDI events; note value is passed as CC value.
  • 13th fret F (note #53) to 22nd fret D (note #62) are xlated to CC89 MIDI events; note value is passed as CC value.   
You need to run the MIDI output of the GR-55 thru the event processor & feed it back into the MIDI input of the GR-55, for the xlated notes to be used as CCs. 

Assigns are used in the attached GR-55 voice as follows:
  • Assigns 1 & 2 are used to xlate CC88 to filter cutoff frequency for PCM voices 1 & 2
  • Assigns 3 & 4 are used to xlate CC89 to LFO1 rates for PCM voices 1 & 2, where they are used for both panning & filter modulation
Very helpful lesson #1: In assigns 3 & 4, I was able to map CC89 values 53-59 (7 values) to rates of 1/32, 1/16, 1/8, 1/4, 1/2, whole & double-whole notes.  I did NOT want the triplets & dot values between each, and note that it skipped 'em!!!   Turns out this makes use of the fact that these 'perfect' (divisible by 2) rates are all exactly 3 selections apart, so mapping 21 possible values into a range of 7 really did work & skip all of the unwanted rates.   Hope this makes sense! 

Very helpful lesson #2: This caught me by surprise... The HOLD function works great with these controllers.  The filter is applied AFTER the HOLD processing.  So you can HOLD a note, then mess with the filter, as is done in the audio example. 

Question - Assigns 5 & 6 don't work.  I wanted the top 3 frets on my E string to all map to a rate of 0.  Maybe you can't map 3 values to 1 value?   Not sure why it doesn't work...

Enjoy!

Shawn

Additional notes...  This patch & code assumes your GR-55 settings under SETTINGS|GTR-MIDI are set to SWITCH=ON, MODE=MONO and STRING CH=11 (i.e., it assumes your E string is getting published on channel 16).  Also, under SETTINGS|GENERAL your PATCH CH=1 (so it responds to your CC values sent on channel 1).
Address the process rather than the outcome.  Then, the outcome becomes more likely.   - Fripp

Elantric

Shawn,
Fantastic post full of great info!
Must get a MIDI Solutions Event Processor myself.




papabuss

Great job, shawn! THX for the detailed info. (+1) ;)
FENDER STRATOCASTER (1974); BRIAN MAY RED SPECIAL; VG 99; GR 55; Yamaha DX 7

Music was my first love and it will be my last (JOHN MILES)

tekrytor

Fine work shawnb! Thanks for all... the effort, creativity, and the excellent documentation!
SY-300/BeatBuddy/VoiceLive 3/GR-55(v1.50)/33/1/50/700/VGA-7/V-Bass, Yam-G10, GPK-4, DIY X-Bee HighlyLiquidCPU "Cozy-Lil-Footie", FCB-1010, other MIDI stuff, Godin Freeway SA and various other GK equipped controllers, Sonar X1, Audacity, KXstudio, Misc devices

strayhorse45

Thanks for all your work on this!

sunbambino