[sdiy] MIDI to CV question - no Triggers?

Scott Gravenhorst music.maker at gte.net
Sat Mar 4 20:34:58 CET 2006 

The Roland GR-50 Guitar Synth allows assigning either a different channel to each string
OR it can transmit it's messages from all six strings on one channel.

If you elect to use one channel, then things act strangely, for example, a pitch bend of
one string will cause all voices which are currently playing sound to also bend,
regardless of which string started them.  If you set it so that each string is on it's
own channel, then each string behaves more guitar-normally, i.e., you can bend one
string's pitch and not others.  The single channel mode allows using running status
effectively for all the notes you play whereas channel per string mode won't be as
effective, especially if you're playing chords.

I don't use the MIDI out on my GR-50 for the most part.  It's too delayed given that the
circuits that decide when a note has been picked introduce a delay and then the MIDI
delay is added on top of that.  The GR-50's internal synth does not get it's note
information via MIDI, it's done directly from the circuits that figure out when to play
a note and what note to play.  Because of that, the internal synth sounds don't suffer
as much from delay.

Michael Bacich <weareas1 at earthlink.net> wrote:
>
>On Mar 4, 2006, at 9:51 AM, D A F wrote:
>Yes, I guess the problem is: What happens when you are holding one  
>note and
>then press down a second note without letting the first one up?
>
>This would not be an issue when using the MIDI-CV with a polyphonic  
>MIDI guitar controller.  Although the guitar is a six-note polyphonic  
>instrument, guitar strings are inherently monophonic.  That is to  
>say, on a guitar,  it is not possible to play two notes  
>simultaneously on one string.  Or potting it another way, you can't  
>"press down a second note without letting the first one up".
>
>Typical guitar-to-MIDI controllers (such as the Yamaha G50 and the  
>Roland GR units) transmit each string's note information on a  
>separate MIDI channel, which would necessitate the use of a separate  
>monophonic MIDI-CV converter for each string.  Such a system would  
>also require hardware for six complete analog synthesizer voices.   
>This may explain why we don't often see people using guitars as  
>controllers for their analog synth gear.
>
>If you wish to use the guitar to play a monophonic analog system, you  
>will have two choices:  Either you must restrict yourself to playing  
>on only one string, or you must re-channelize the six-channel MIDI  
>info coming from the guitar so that it all comes out on the same MIDI  
>channel.  This could be done with some kind of external MIDI  
>processing device, such as a MOTU MIDI Time Piece II.  However, this  
>would necessarily open up a stinky can of Pandora's Worms, in terms  
>of some potential MIDI problems and some note and trigger assignment  
>problems -- for instance:  What happens if you play two notes at  
>once?  What happens if you play a note, then the same note on two  
>different strings?  What if you don't completely release the first  
>note before hitting the next?  Which note takes Note-On and/or Note- 
>OFF precedence?  Which note's Velocity takes precedence?  What if you  
>bend a note or notes? And getting back to the original question, what  
>happens with triggers and gates if you press a second note without  
>letting the first one up?  ...there are other potential problems, too.
>
>Harry Bissell has opened that can of worms many times, and has come  
>up with various solutions for most of the inherent problems -- none  
>of them involving MIDI, though.  Check out his "Muffy" guitar to CV  
>converter for more insight:
>
>http://www.bitshifted.com/SDIY2004/muffy.asp
>
>
>
>Content-Type: text/html;
>	charset=ISO-8859-1
>
><HTML><BODY style=3D"word-wrap: break-word; -khtml-nbsp-mode: space; =
>-khtml-line-break: after-white-space; "><DIV style=3D"margin-top: 0px; =
>margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal =
>normal normal 12px/normal Helvetica; min-height: 14px; "><BR></DIV><DIV =
>style=3D"margin-top: 0px; margin-right: 0px; margin-bottom: 0px; =
>margin-left: 0px; ">On Mar 4, 2006, at 9:51 AM, D A F wrote:</DIV><DIV =
>style=3D"margin-top: 0px; margin-right: 0px; margin-bottom: 0px; =
>margin-left: 0px; "><FONT class=3D"Apple-style-span" =
>color=3D"#2100DD">Yes, I guess the problem is: What happens when you are =
>holding one note and</FONT></DIV><DIV style=3D"margin-top: 0px; =
>margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><FONT =
>class=3D"Apple-style-span" color=3D"#2100DD">then press down a second =
>note without letting the first one up?</FONT></DIV><DIV =
>style=3D"margin-top: 0px; margin-right: 0px; margin-bottom: 0px; =
>margin-left: 0px; font: normal normal normal 12px/normal Helvetica; =
>min-height: 14px; "><BR></DIV><DIV style=3D"margin-top: 0px; =
>margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">This would =
>not be an issue when using the MIDI-CV with a polyphonic MIDI guitar =
>controller.=A0 Although the guitar is a six-note polyphonic instrument, =
>guitar strings are inherently monophonic.=A0 That is to say, on a =
>guitar,=A0 it is not possible to play two notes simultaneously on one =
>string.=A0 Or potting it another way, you can't "press down a second =
>note without letting the first one up".=A0=A0</DIV><DIV =
>style=3D"margin-top: 0px; margin-right: 0px; margin-bottom: 0px; =
>margin-left: 0px; font: normal normal normal 12px/normal Helvetica; =
>min-height: 14px; "><BR></DIV><DIV style=3D"margin-top: 0px; =
>margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">Typical =
>guitar-to-MIDI controllers (such as the Yamaha G50 and the Roland GR =
>units) transmit each string's note information on a separate MIDI =
>channel, which would necessitate the use of a separate monophonic =
>MIDI-CV converter for each string.=A0 Such a system would also require =
>hardware for six complete analog synthesizer voices.=A0 This may explain =
>why we don't often see people using guitars as controllers for their =
>analog synth gear.</DIV><DIV style=3D"margin-top: 0px; margin-right: =
>0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal =
>12px/normal Helvetica; min-height: 14px; "><BR></DIV><DIV =
>style=3D"margin-top: 0px; margin-right: 0px; margin-bottom: 0px; =
>margin-left: 0px; ">If you wish to use the guitar to play a monophonic =
>analog system, you will have two choices:=A0 Either you must restrict =
>yourself to playing on only one string, or you must re-channelize the =
>six-channel MIDI info coming from the guitar so that it all comes out on =
>the same MIDI channel.=A0 This could be done with some kind of external =
>MIDI processing device, such as a MOTU MIDI Time Piece II.=A0 However, =
>this would necessarily open up a stinky can of Pandora's Worms, in terms =
>of some potential MIDI problems and some note and trigger assignment =
>problems -- for instance:=A0 What happens if you play two notes at =
>once?=A0 What happens if you play a note, then the same note on two =
>different strings?=A0 What if you don't completely release the first =
>note before hitting the next?=A0 Which note takes Note-On and/or =
>Note-OFF precedence?=A0 Which note's Velocity takes precedence?=A0 What =
>if you bend a note or notes? And getting back to the original question, =
>what happens with triggers and gates if you press a second note without =
>letting the first one up?=A0 ...there are other potential problems, =
>too.</DIV><DIV style=3D"margin-top: 0px; margin-right: 0px; =
>margin-bottom: 0px; margin-left: 0px; font: normal normal normal =
>12px/normal Helvetica; min-height: 14px; "><BR></DIV><DIV =
>style=3D"margin-top: 0px; margin-right: 0px; margin-bottom: 0px; =
>margin-left: 0px; ">Harry Bissell has opened that can of worms many =
>times, and has come up with various solutions for most of the inherent =
>problems -- none of them involving MIDI, though.=A0 Check out his =
>"Muffy" guitar to CV converter for more insight:</DIV><DIV =
>style=3D"margin-top: 0px; margin-right: 0px; margin-bottom: 0px; =
>margin-left: 0px; font: normal normal normal 12px/normal Helvetica; =
>min-height: 14px; "><BR></DIV><DIV style=3D"margin-top: 0px; =
>margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><A =
>href=3D"http://www.bitshifted.com/SDIY2004/muffy.asp">http://www.bitshifte=
>d.com/SDIY2004/muffy.asp</A></DIV><DIV style=3D"margin-top: 0px; =
>margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal =
>normal normal 12px/normal Helvetica; min-height: 14px; "><BR></DIV><DIV =
>style=3D"margin-top: 0px; margin-right: 0px; margin-bottom: 0px; =
>margin-left: 0px; font: normal normal normal 12px/normal Helvetica; =
>min-height: 14px; "><BR =
>class=3D"khtml-block-placeholder"></DIV></BODY></HTML>=
>

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-- Scott Gravenhorst | LegoManiac / Lego Trains / RIS 1.5
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