MIDI - CV/Gate converter patch

valibali

Hi masters, does anybody know something about MIDI - CV converting by kX?
Or are there any ways (by my EMU-based sound card, with kX) to convert the MIDI sing of a keyboard to a CV and Gate sing?
It is very recommended for my analog modular synth. (And I'm not able to build a CV keyboard)

regards: valibali

Maddogg6

I am not understanding exactly what you seek??

A CV = as in a pedal (usually a volume pedal, or a Damper Pedal) that plugs into a MIDI keyboard / MIDI Controller via a 1/4" plug and can potentially send MIDI Continuous Controller (aka 'MIDI CC') messages out its MIDI OUT port - or receive via MIDI IN port to mimic or automate the actions of a CV in the form of MIDI CC messages.

The short answer - (assuming you used 'CV' in the way I described) - is no - something needs to convert the 1/4" plugs output into a MIDI OUT - there are DIY projects to do this with microcontrollers - or a MIDI controller that has CV inputs can probably do this as well..

Once converted to MIDI - kX can do quite a bit - and if not, MIDI OX can convert midi CC's

But your use of 'sing' is something that I am not following exactly??

valibali

Hi,
"CV" - i mean 'control voltage' - is used to control the 'voltage controlled oscillators' (VCO), 'voltage controlled filters' (CVF), or 'voltage controlled amplifiers' (VCA) and some other modules of an analog modular synth. Yeah, they were on top in the previous century...
The original CV range is 1V/Oct.

Well, there are a (n unworking) way to convert the MIDI to this CV by a PC wich has a LPT port. There is a digital-analog converter (DAC) patched to the printer port.

BUT! Unfortunately this software can't be installed to my PC.
I have to control with something my modular synth, and I have a MIDI keyboard, so I realized that there must be a way to convert the MIDI to this CV.
CV/Gate - Wikipedia, the free encyclopedia

'sing' - mistyping ->'sign', MIDI sign maybe i should buy an another PC keyboard...

regards
vb

Maddogg6

so you want to convert MIDI CC to a CV?

There exists a language called FreeBASIC that would make writing a program to output to the printer port (LPT) rather easy if you already have the D/A (digital to analog) converter. (even in Win XP)
It is capable of taking a MIDI IN and output to LPT for a PC based DIY project.
(may need MIDI YOKE / MIDI OX)

Then there exists a DIY project that uses a microcontroler (instead of a PC) that converts MIDI to CV (PAIA has a lot of stuff, and have been around for quite sometime)
PAiA - 9700K MIDI2CV8 Electronics Kit, MIDI to CV Converters, 9700K
PAiA - MIDI to CV Converter

Its rather expensive imho... $122 US for a kit. But capable of 8 CV outs and eliminates the need for a PC from the setup.

valibali

Hi,
Thank you very much.
This PAiA stuff is really good, man!
8 CV OUTs, it is made for me. But...(of course) it isn't cheap.

Well, firstly i'll try DIY.

Thanx again,
bests,
vb

Maddogg6

glad to help - if you get it built - I would be interested in hearing about your experience with it.

valibali

Well I have found a nice schematic with PCB, and part layout.
http://www.musicfromouterspace.com/a...th/midi2cv.htm

it looks great, but there are some parts without any detail...
not good

is it possible to do this conversion with a kX project plugin?
i mean
from a keyboard to the MIDI port of my sound card
and the CV/Gate and TRIG OUT might could be the LINE OUT.

what do you think?

by the way, i think i should buy the book called 'Programming sound cards in Assembly an Pascal'

bye,
vb

Maddogg6

due to the likely DC de-coupling of most audio signal paths - using a line out as a gate or a CV is not likely possible (at least with out modifying your sound card). And then, I am not absolutely sure.

Sorry, I don't have an easy answer more than I already have given.
you are better off connecting a DAC to the LPT port and use what ever language to convert MIDI IN and output accordingly to LPT port - but the easiest way to do that, imho, is with FreeBASIC. Unless you are already familiar with Pascal (or any other language) - you likely wont use anything more than your sound cards MIDI port, which is accessable via WinAPI (edit: and a dll to access lpt port hardware directly - that freebasic has built in /edit).

Of course - there is always a way to convert a car into an airplane - its not usually practical. So its not like I am saying its not possible - I am saying I don't know if it would work, I am pointing out ways that I have most confidence in working. Anything else would take some educated investigating that is beyond me/my skills. But maybe someone else here has more insight??

Russ

You might take a look at the following link as well (although some of it is only in French):
Papareil Synth Labs - MIDI

Maddogg6

Just a warning - that DIY assumes you have the ability to upload 'firmware' into a PIC chip microcontroller (read: you have a PIC 16F628 chip programmer to connect to your PC) - where PAiA offered a pre-programmed one as part of the kit.

Russ

Yes of course, but it is simple enough to build a PIC programmer for the chips used in those projects.

i.e.
Check out the El Cheapo PICmicro Programmer, and similar projects found easily enough on the web.

valibali

Hi all,
Well - i think - i have managed to solve the problem.
I found this:Synth schematics--::--
I have downloaded the modular version, it is working on Win98 (It is not working on XP or 2k at all!!!)
Now I am working on the schematic of the DAC, it will provide 88 CV OUT with portamento (glide) without any PIC or AVR!!!!
I am going to upload it with PCB design as soon as finished. (EAGLE is very slow in difficult PCB wiring.)

regards:

vb

stylus02

i could imagine using an ac- voltage, out of an sinoid oscillator, rectified after the soundcard out's to have a dc. for a gate this could work . but you surely know that most analog synths use an exponential cv, which is very stable. the card can do exponential calculation. but what happens after rectifying it externally the card ? to find the correct tune could be a very trying task.

stylus