control voltage from the digital realm [no not midi to cv]

[matt the fiddler]

please don't lynch me form this post.... i am an analog snob

while I will never change out my filtering to software, though I think there much more "digital/ software" control voltage that we can get for our foogers and synths other than then midi to cv converters. I just haven't found anything yet.....

[I do use my midi to CV a lot, but it has major shortcomings]

does anyone know of any racks/ cards/ modules, etc. which link to a computer and output better control voltage than MIDI.,

if we could do that, we could write sequences or have any software controlled control voltage .. heck even the ability to link to the 960 in the arturia programs would be sweet.

[earsmack]

Maybe not exactly what you're looking for but ever since I started exploring CV (with my Voyager/RingMod/VX-351/Frostwave Resonator I've looked for ways to expand upon it as well.

A couple nice things I found were my Korg Poly 61 can take a trigger input for the arpeggiator and my DSI MEK can not only process incoming audio but also 2 CV signals that can then be used to alter just about any param you can think of. Really great synth since it contains a 4-track analog-style arpeggiator and has both analog (2) and digital (2 more) oscillators and some crazy filters, etc.

Once again, not CV, but I've been using my Voyager Mix In to route all sorts of stuff through my setup. I route audio into the Voyager and then from there it goes through various CV-controlled effects, etc.

Although it is probably overkill I can easily run the Nord Electro through the Voyager, then through the effects listed above plus a fuzz and delay, then into the DSI MEK then into a Virus TI and finally out to tape. You can get some really wild sounding stuff running through the Moog filter, the MS20 filter on the Frostwave, the Curtis filter on the DSI MEK and then through the Virus TI! Wierd Wild Stuff!

Sorry to go sorta off-topic here...but half of this signal path is analog

[matt the fiddler]

i run through a variety of effects and distortions both on my computer, tube amps, leslie's, other analog, and my harmonically convergized bossgt-8. I just want the compositional power to really have control over CV... I want to do things with control that don't exist or would take $1000s and many modules to achieve. i am starting to look at MAx Msp and the like to see if there is anyway I can utilize that program.... since it is user configurable, it suites me well


Man, what I wish existed was a group that used MAXMSP/ cycling 74 to control modular synths it isn't THAT far a strech to get there.... I just need an interface....

[jamirokid]

Hey Matt! I was thinking...you want a new creative way of controlling CV's. How about using the audio out of your audio interface. You could just record a sine wave for a long time in your DAW then cut it up, meaning messing with the amplitude of the wave. It seems like this would affect the signal strength and you could get some great sweeps or stutters buy drawing the volume in protools or whatever. I'm not really sure how much voltage could come out of an audio out on an interface, but I do know I use an audio out of my MOTIFES to sync my murf. I guess you could get a voltmeter or whatever and measure the amount of voltage coming out the output. I might try it!
Josh

[matt the fiddler]

I have thought of that, but most sound cards are rated at 20-22K etc. i don't think many sound cards output either offset voltage or LFO type modulation.


am I wrong in this? it would be a INCREDIBLY EASY fix if I am...

[Tangsonghe]

If your voltages ain't right or your output
impedances too low then all you need to do is
wire up the output of the soundcard to an op
amp with the correct gain and offset to make your CV.
The outputs of a soundcard have capacitative coupling
so if you want changes in voltage of less than 5 Hz you'd
need to short out the capacitors on your soundcard.

Another way which I use is to buy a cheap national instruments
D/A card and use Labview. Labview is a graphical programming
platform. You can make any output you like and make make
a front panel with controls for manipulating the output. You'll
need a friend who can 'loan' you a copy of Labview as it is
quite expensive ($1000).

[electrical_engineer_gEEk]

Another way which I use is to buy a cheap national instruments
D/A card and use Labview. Labview is a graphical programming
platform. You can make any output you like and make make
a front panel with controls for manipulating the output. You'll
need a friend who can 'loan' you a copy of Labview as it is
quite expensive ($1000).

unless you bought the student copy in college for less then $100
cha ching!

[matt the fiddler]

can you post an example of a "cheap national instruments
D/A card and use Labview" so I can start my quest?

i can't find anything-- though i did find a lot of texas instruments digital to analog chips that operate in the 5 volt realm.. =P

i did find this- which could be nice... but I can find it for sale...
http://www.bmf.hu/conferences/sisy2006/16_Soos.pdf


also labview seems crazy big... would i look for the full version, or for a sound specific piece of their software....


glad I asked on here.. i think there is a lot to be found if I keep digging...

[Kevin Lightner]

Fwiw, I use an Apple II with A/D and D/A boards.
One can read in a voltage, store it to memory and then play it back.
The cool thing is that anything can be done with the data in between, even in realtime.
Since it's programmable in BASIC, it's easy to write small programs that do whatever.
One could take in CV's, divide them, invert them, limit them, etc, etc.
This is definitely not for everyone, of course, but it's one way of doing things.
I also admit that my Apple II is very much sped up over a stock one.

I actually use this ancient machine in service too.
For example, I can plot bar graphs of all 16 env generators in a Jupiter 8.
Since each env has an internal time adjustment and you want them all equal, making it visual is the easiest way to get there.
Otherwise you have to use a stopwatch on each env separately.
Not fun.

[Tangsonghe]

I'll get back to you about cards. National instruments cards
are probably a bit expensive given your budget. A friend of mine
said that there are plenty of second party manufacturers that make
cards that are compatible with the Labview drivers but I'll need to
ask him of their names. Check ni.com to see the kinds of cards
available. You may be able to pick something up second hand.
Even if you get a soundcard or non labview compatible DA AD card
you can still address it using Labview (you'll just need to figure
out the communications protocol yourself).

With regards to labview. Find a friend who is at a University and
see if you can pick up a copy of 7.0 or 8.2. The basic version will
probably do (it contains fewer black box subroutines but I doubt you'd
need them). You need MAX as well which drives the cards. Labview
itself is amazing! You can achieve very complicated control and
input very quickly. You basically wire up different boxes on the
screen and wire the boxes to a control panel. The boxes can be
signal generators, signal analysis, math operations, outputs, inputs
etc and your front panel can have a variety of knobs, switches, inputs and graphs. Once your 'virtual instrument' is finished you hit play and it does its
thing. When you want to change things, editing is very easy - much
easier than script programming.

I use it at work to control a very compicated laser experiment with
15 detectors (inputs) and 30 motors (outputs). I couldn't imagine
doing that any other way (though I did used to use Fortran and BASIC!).

My dream is to build a set of voicecards (each card a monosynth)
and bring them together as a polyphonic synthesiser using Labview
to coordinate notes and modulations......

[matt the fiddler]

hmm.


we the 2 sound cards i have now are:

motu 828 mk2 rack
soundblaster audigy2

neither of which i think can read voltage..
i am fine purchasing new cards, with in reason especially if I can program some specifiv voltages.



finally, this is quickly getting more complex than i invisioned. are there forums or groups where people are writing these codes and doing the hacking we are talking about?

[eric coleridge]

Matt,

I remember reading about circuit that was up on one of the big Synth DIY sites to make a device that would accept a printer port cable and output control voltages (plus a corresponding software). It allowed you to output 8 or 16 sepeperate CVs and gates... most likely for sequencing, etc...
I remember it was for PC, which I don't own.

maybe if you do some google searches along these lines you'll find it. I'll take a look for it also.

Also, I've seen some DIY sites that sell various Digital/Analog micro-controllers... just chips and PCBS for incorporating into various projects. I'm sure some were designed specifically to use with MAX/MSP. These micro-controllers are used in lots of different applications, but could be adapted for CVs. Look up digital/analog and microcontroller (if you haven't thought of that already...).

[matt the fiddler]

i am on both macs and pcs, so what ever i can find that works... though i would prefer a pc setup right now... as my mac is old and out of date...

[Lengai]

You'll have to research finding one, but the PSIM-1 may be something you'd like:

http://www.synthmodules.com/psim-1.htm

[MC]

I'm a Labview expert (made a career with it since 1994) and have worked with a variety of National Instrument I/O boards. They do have low density I/O modules but NI stuff is not cheap. There are other makes of analog I/O boards out there, many of them supply Labview drivers.

I even went as far as designing a full panel of virtual knobs and buttons for my Oberheim MAtrix-6R, but there weren't any MIDI drivers for Labview at the time and by the time there were, the M6R was gone.

I designed a Labview VI that grabs audio from my soundcard. It detects silent gaps and breaks an audio tape into separate WAV files. I just hit PLAY and leave it alone. Way cool

I'm a professional software developer and Labview is my favorite software. Very well designed, excellent debugging tools, slick interface, and downright robust and rugged when designed right. BTW the base package starts at $2000, not $1000. I have the $3000 professional version, you would need that if you want to build a standalone executable otherwise the base is all most hobbyists need. Although LV appears to take up a lot of space, you can unselect modules you don't need.