You are here

CV to MIDI convertor.

Customising, building or repairing your own gear? Need help with acoustic treatment or soundproofing? Ask away…

CV to MIDI convertor.

Postby forumuser927284 » Tue Jul 01, 2014 12:57 pm

Hi, does this exist? I haven the Kenton Pro 2000 mk2 but think it only works the other way.

I want to control a midi synth from my MC202.

Cheers
forumuser927284
Regular
Posts: 161
Joined: Wed Feb 12, 2014 1:00 am

Re: CV to MIDI convertor.

Postby Mixedup » Tue Jul 01, 2014 1:08 pm

I think Analogue Solutions used to do one. But my knowledge of this market is poor at best!
User avatar
Mixedup
Jedi Poster
Posts: 4372
Joined: Wed Sep 03, 2003 12:00 am
Location: Cambridgeshire, UK

Re: CV to MIDI convertor.

Postby BJG145 » Tue Jul 01, 2014 6:49 pm

There are MIDI retrofits...

http://mungo.com.au/midiretrofits.html

...assuming it also does MIDI out. A standalone unit doesn't seem easy to find, though there must be one somewhere...
User avatar
BJG145
Frequent Poster (Level2)
Posts: 3874
Joined: Sat Aug 06, 2005 12:00 am

Re: CV to MIDI convertor.

Postby forumuser927284 » Tue Jul 01, 2014 8:12 pm

Thanks guys. So, it waste trust my lack of goggling. Odd, you;d think someone somewhere would have made something like this.

Don't want to retrofit if I can help it. Like to keep these classics as god intended :)
forumuser927284
Regular
Posts: 161
Joined: Wed Feb 12, 2014 1:00 am

Re: CV to MIDI convertor.

Postby The Elf » Tue Jul 01, 2014 8:39 pm

Expert Sleepers Silent Way can do this, but I think you're just making life difficult for yourself...
User avatar
The Elf
Jedi Poster
Posts: 12922
Joined: Tue Aug 14, 2001 12:00 am
Location: Sheffield, UK
An Eagle for an Emperor, A Kestrel for a Knave.

Re: CV to MIDI convertor.

Postby BJG145 » Tue Jul 01, 2014 10:22 pm

I think something by Expert Sleepers or Analogue Systems, or Analogue Solutions, might require a modular setup.

http://www.analoguesolutions.org.uk/concussor/cvm.htm
http://www.soundonsound.com/SOS/sep04/a ... ers300.htm

Seem to be some Arduino/DIY solutions as well, but...er...that's about it. Surprised.
User avatar
BJG145
Frequent Poster (Level2)
Posts: 3874
Joined: Sat Aug 06, 2005 12:00 am

Re: CV to MIDI convertor.

Postby BillB » Wed Jul 02, 2014 7:43 am

If you can track down a Novation BassStation Rack (the first model, not the Super BassStation rack), it has CV inputs which convert to MIDI. And vice-versa. P18 of the manual says:

CV/Gate To MIDI Convertor Vintage analogue synths which use Control Voltages ( CV ) to determine the pitch of the oscillators and a Trigger Pulse ( Gate ) to open the envelopes can be interfaced with the BassStation Rack and any other MIDI device using this feature. The different types of CY/Gate system used on these older synths can also be set.

Plus you get a great little monosynth! They do come up from time to time, £100-200.
BillB
Frequent Poster
Posts: 745
Joined: Mon Apr 07, 2003 12:00 am
Location: East Yorkshire

Re: CV to MIDI convertor.

Postby Richie Royale » Wed Jul 02, 2014 6:45 pm

BillB's suggestion is good.

There are modular modules that do it, but this Doepfer one is 134 Euros, low stock and you'll need someting power it which is another outlay, so the Basstation sounds like a good move.

http://www.schneidersladen.de/en/doepfer-a-190-1-midi-cv-interface.html

There are various others

http://www.modulargrid.net/e/tags/view/10
User avatar
Richie Royale
Jedi Poster
Posts: 4597
Joined: Tue Sep 12, 2006 12:00 am
Location: Bristol, England.
http://soundcloud.com/richie-royale 

Re: CV to MIDI convertor.

Postby forumuser927284 » Wed Jul 02, 2014 8:19 pm

Bill - Thanks mate. I have even owned the Bass station rack years ago and never knew it could do this. I knew of its MIDI to CV capability but not the other way around.

Thank you.
forumuser927284
Regular
Posts: 161
Joined: Wed Feb 12, 2014 1:00 am

Re: CV to MIDI convertor.

Postby BillB » Thu Jul 03, 2014 11:12 pm

Another thought, along similar lines, and at least with kit which is currently available. I just noticed on this website
http://www.ebay.co.uk/itm/Korg-Monotribe-Midi-in-and-out-mod-kit-/150977363921?pt=Keyboards_MIDI&hash=item2326f3bfd1
which is for a Korg Monotribe MIDI interface, it points out that the latest firmware upgrade for the Monotribe allows CV input, with the note values being reflected at MIDI out (when fitted with the MIDI kit). Personally I would want to find somebody on the net doing this CV>MIDI conversion successfully, before shelling out for Monotribe, MIDI I/O plus import duty - but it's an option.
And it gets you another nice little monosynth 8-)
BillB
Frequent Poster
Posts: 745
Joined: Mon Apr 07, 2003 12:00 am
Location: East Yorkshire

Re: CV to MIDI convertor.

Postby Richie Royale » Fri Jul 04, 2014 6:11 pm

I saw this the other day, a touch expensive but an interface both ways it seems, and more

http://www.teenageengineering.com/products/oplab
User avatar
Richie Royale
Jedi Poster
Posts: 4597
Joined: Tue Sep 12, 2006 12:00 am
Location: Bristol, England.
http://soundcloud.com/richie-royale 

Re: CV to MIDI convertor.

Postby ambianimaton » Tue Oct 29, 2019 7:14 am

here is a project I am working on that should work it tracks ten octaves. it tracks each octave evenly over twelve steps so no difference between whole and half steps. it is for arduino or attiny 85. you will need a 10k resistor between the note and velocity inputs and the analog pins on the board to deal with negative voltages and another one to ground. you will also need to build an arduino midi out circuit on pin one tx. the channel is selected with a knob, get linear instead of exponential potentiometers the note can also be selected with a knob. I have not tested this device I just wrote the code the other day and designed the panel. if you have access to a laser cutter you can engrave or drill the panel depending in the strength of the laser. here is the code.



void setup() {  Serial.begin(31250);


}
void loop() {
  int gate=digitalRead(3);
int levelvel =analogRead (A0);
levelvel =100;
int ch= analogRead (A1);
int note =analogRead (A2)||analogRead(A3);
ch=map(ch,0,1024,0,16);
levelvel=map(levelvel,0,1024,0,127);

note=map(note,0,1024,3,123);
  if(gate==HIGH)
{Serial.print(ch);
Serial.print(note);
Serial.print(levelvel);}

}
ambianimaton
Posts: 2
Joined: Tue Oct 29, 2019 6:42 am

Re: CV to MIDI convertor.

Postby The Red Bladder » Tue Oct 29, 2019 1:53 pm

Sonuus do a pitch-to-MIDI converter called the G2M. It's a bit dodgy on battery power but is fine with a pukka PSU. I use it quite a bit and it's a very useful bit of kit.
The Red Bladder
Frequent Poster (Level2)
Posts: 2265
Joined: Tue Jun 05, 2007 12:00 am
Location: . . .
 

Re: CV to MIDI convertor.

Postby James Perrett » Tue Oct 29, 2019 2:35 pm

If you move your eyes to the right while browsing the SOS forums chances are you'll see and ad for this

https://kentonuk.com/product-category/c ... onverters/
User avatar
James Perrett
Moderator
Posts: 8527
Joined: Mon Sep 10, 2001 12:00 am
Location: The wilds of Hampshire
JRP Music - Audio Mastering and Restoration. JRP Music Facebook Page

Re: CV to MIDI convertor.

Postby ambianimaton » Tue Oct 29, 2019 5:35 pm

i apologize, i had to update the code to denote message type and send note off messages



void setup() { Serial.begin(31250);


}
void loop() { int noteon=9;
int noteoff=8
int gate=digitalRead(3);
int levelvel =analogRead (A0);
levelvel =100;
int ch= analogRead (A1);
int note =analogRead (A2)||analogRead(A3);
ch=map(ch,0,1024,0,15);
levelvel=map(levelvel,0,1024,0,127);

note=map(note,0,1024,4,123);
if(gate==HIGH)
{ Serial.print (noteon);
Serial.print(ch);
Serial.print(note);
Serial.print(levelvel);}
if(gate==LOW)
Serial.print (noteoff);
Serial.print(ch);
Serial.print(note);
Serial.print(levelvel);}
{
}
ambianimaton
Posts: 2
Joined: Tue Oct 29, 2019 6:42 am

Re: CV to MIDI convertor.

Postby James Perrett » Tue Oct 29, 2019 10:01 pm

Don't you need some kind of interrupt so that the code only sends notes when the state of the gate input changes? As it stands you'll be sending a constant rapid stream of note ons or note offs.
User avatar
James Perrett
Moderator
Posts: 8527
Joined: Mon Sep 10, 2001 12:00 am
Location: The wilds of Hampshire
JRP Music - Audio Mastering and Restoration. JRP Music Facebook Page

Re: CV to MIDI convertor.

Postby EnragedDeveloper » Fri Nov 08, 2019 10:05 pm

ambianimaton wrote: you will need a 10k resistor between the note and velocity inputs and the analog pins on the board to deal with negative voltages and another one to ground.

Admittedly, I haven't dealt with CV equipment, but this sounds like you might want 1 or two optocouplers in this interface. Definitely one on the MIDI to microcontroller leg, and the other on the CV side if that equipment carries any kind of charge on its pins. Apparently the speed of the MIDI spec makes the most commonly used one (6N138) problematic.

This is theoretically a better one to use: H11L1 from Digikey.
I say theoretically because I haven't had any experience with it, personally...
You can get them for about $0.35 each on Amazon.
H11L1 vs 6N138 optocoupler reference post: StackExchange Electronics
EnragedDeveloper
Posts: 2
Joined: Fri Nov 08, 2019 9:29 pm


Who is online

Users browsing this forum: No registered users