MIDI-CV polyphony

[quamen]

Is the MIDI-CV polyphonic to eight voices?

Can I use it to control eight different notes on the same MIDI channel? Will a gate be assigned to each of the eight note events?

Thank you.

Q

[Davo]

Because voltage determines pitch, envelope, gate, velocity, etc; CVs are inherently monophonic.  You can get polyphony using CVs, but you must manually set up each additional voice.  Peruse http://www.synthesizers.com and you'll find more in-depth discussion of what CV is and how it's used.  If you're thinking about running the output of, say, and MBSID through a Moog-style ladder filter, you need at least one CV channel to control the filter.  Then you can run whatever audio signal you want through the filter.

[quamen]

Thanks for the reply.

I understand what CV is and how it controls analog instruments.

My question is regarding specifically how the MIDIbox MIDI-CV works.

I have monophonic MIDI-CV convertors. MIDI goes in and pitch CV and gate go out. The voltage determines the pitch usually 1volt per octave on VCOs. The gate is used to trigger envelope generators.

I also have a polyphonic MIDI-CV made by Paul Maddox and Tony Allgood. It uses a microcontroller. http://www.modulus-music.com/products/modular/polydac/

My question is if the MIDIBox MIDI-CV will act as a polyphonic MIDI-CV convertor.  For example, if I play a chord of the notes  A, C, F, E on a MIDI keyboard. What will the MIDI-CV do with that MIDI data?  Will it split it into four different CV pitch voltages? One voltage per note? Will it send a gate signal for each CV signal? What happens if I play another four-note chord?

The polyphonic CV convertor I have does that. It will send a corresponding CV for each note played and a gate signal for each note played. It will do this up to four voices. If a new note is played it will stop the first note played and play the new note. I am curious if the MIDIBox MIDI-CV will do the same.

Thanks again

Q

[moebius]

Maybe reading MIDIbox CV Design page would help? ;D

http://www.ucapps.de/midibox_cv.html

Bye, Moebius

[quamen]

Thanks Moebius.

I had read it previously but still was confused about how it handles the gate signals.

To quote the MIDI- CV page:

"Poly assigns all played keys to different channels. The first note will always be forwarded to CV output #1, the second to #2, to third to #3 and so on if the appr. channels are assigned to Notes in the MIDI event menu. This means, that you are still able to use the last channels for other MIDI events."

Does this mean that it sends a gate signal at the beginning of every MIDI note? Are they assigned to corresponding gate channels-ie  cv note 1 with gate 1, cv note 2 with gate 2, etc.?

How does the MIDI CV handle new notes? If the MIDI-CV is set to four voice polyphony and a four note chord is being played what happens when a new note is played? Does it drop the first note  played?

I know I am asking a lot of questions. It may be easier for me just to build the MIDI-CV and eaperiment.

Once again thanks to anyone who can help.

Q

[TK.]

Hi,

Does this mean that it sends a gate signal at the beginning of every MIDI note? Are they assigned to corresponding gate channels-ie  cv note 1 with gate 1, cv note 2 with gate 2, etc.?

yes... but it's maybe better to say: the oldest note is assigned to CV 1/gate1

Each note has it's seperate CV and gate output

How does the MIDI CV handle new notes? If the MIDI-CV is set to four voice polyphony and a four note chord is being played what happens when a new note is played? Does it drop the first note  played?

MIDIbox CV uses the same Poly algorithm like MIDIbox SID: each new note will pushed into a stack, each released note will be removed from the stack. So long the stack is full (SID: 3 notes, CV: 8 notes), additional notes won't be accepted

Sidenote: MIDIbox FM provides an optimized stack handling: once the stack is full, the "oldest" note will be dropped, resp. replaced by the new note

Best Regards, Thorsten.

[quamen]

thanks, TK

One more question:

The MIDI-CV has eight (8) CV signals.

How many gate signals can the MIDI-CV output?

Thanks again

Q

[raphael]

How many gate signals can the MIDI-CV output?

Have you realy read the CV page ???

(Hint: 3rd line in the feature list on top of the page)

Raphael

[quamen]

Yes, I know it says 10 gate signals.

But the schematic of the AOUT shows 2 gate signals??

[raphael]

From main.asm of the midibox_cv_v1_0 application:

; use PORTA and PORTE (J5 of the core module) for 8 additional gate outputs

#define ENABLE_J5 0

Just set this define to 1 and you'll have the additional 8 Gates at pins A0-A7 of the Core :)

Raphael