What he said!
Laser info, etc.:
http://www.pangolin.com/CADA-MOD.htmI can't cite specific soundcards/audio interfaces that pass DC in or out, but I've seen their
use touted for LFOs,etc. I have an RME ADI-2 AD/DA which is fairly high end (or medium,
anyway - it ain't a Lavry!) which supposedly on earlier models than mine would pass DC
both ways - not usually a good thing in audio. Even Massenburg (father of parametric EQ)
said caps are bad, but uncompensated DC offset can be worse, isn't that why a lot of Class
A stuff uses transformers? (Sorry, wrong group!).
Anyway, I don't think bit depth is the problem with resolution, but linearity in the DC to 20
Hz range, since that's out of their intended operating window. So, for other than precision
pitch control this kind of adapted hardware can work and you can create DC to 20 Hz
program in probably any audio editor with a pencil or other waveform editing tools.
Basic "Ghost Electronics" ala Morton Subotnick and Andre Stordeur, using a tone and VCA
to encode and that amplitude shaped tone and an envelope follower to decode, translates
well to digital recording and those "Ghost Tones" can be edited and synthesized in the the
computer, all with off-the-shelf hardware and software. But matched VCA and envelope
follower linearity is a problem for precision.
Yes, I think if you (Paul S.) make the hardware they (software developers) will come or
you'll get stuck with a bunch of hardware!
Barry S.
--- In motm@yahoogroups.com, Mark <yahoogroups@...> wrote:
>
>
> I posted about this to the synth-diy list several years ago. I also
> believe I made similar comments when Synthesis Technology announced
> plans to release a MIDI to CV converter. I don't remember getting
> much of a response.
>
> I completely agree that MIDI is outdated and that we need a "fast
> event information and high resolution continuous control". However,
> I do not think we need a standard so much as we need a product, and I
> am surprised that with all of these companies offering analogue synth
> modules that no one is offering such a product. Nor do I have any
> idea why, as I am sure it would be extremely popular.
>
> I have read that people have used ADAT's as CV recorders by removing
> filter caps on their inputs, but I have never tried that myself, and
> I do not know how well it would work. Regardless, the issue is
> getting from a computer sequencer to CV.
>
> There are two issues here, hardware and software.
>
> I do not know about any cheap audio interfaces that can pass DC.
> Perhaps they can. Nor can I respond to what Paul S. might have said
> regarding their resolution in the sub-sonic range. As far as I can
> remember, the Roland SH-101 used a 6-bit DA driving a CEM3340, and I
> never had any trouble keeping mine in tune. Also, afaik, my Kenton
> Pro-4 is only 12-bit and seems to work fine. So 16 or 24 converters
> -- which are much less expensive now than they were several years ago
> -- would have more than enough voltage resolution for accurate pitch
> control. Both USB and Firewire have much greater bandwidth than MIDI.
>
> So let's say the hardware is a device that has a USB input and
> several CV/gate/trigger outputs. The software issue is that DAW's
> are not designed to to generate DC voltages, so recognizing the
> hardware as an audio interface would not work. However, all DAW's
> support virtual instrument plugins in AU, VST, or some other format.
> So by using a plugin the DAW would simply see the hardware as just
> another MIDI instrument.
>
> Not only would the resulting CV be as accurate as a MIDI to CV
> converter, and allow for much better implementation of pitch bend and
> portmanteau, but the triggers and gates generated would have much
> better timing than MIDI. Imho, that alone would be worth the price
> of admission. Unlike MIDI, it could be able play several several
> events exactly at the same time.
>
> I would recommend that the specs for the hardware be publicly
> available, and that the manufacturer should consider offering some
> sort of SDK to encourage third-party development. Stand-alone
> applications could be developed with computer sequencing abilities
> that go far beyond the limitations of MIDI. Not only could the
> hardware to generate LFO's, envelopes, clocks, and continuously
> sweeping voltages, but given the ability to produce frequencies in
> the audio range, it can be used as a synthesizer itself. By adding
> audio inputs to the software, it could work as envelope follower or
> pitch to CV converter.
>
> Further, the hardware would have a multitude of other uses. Software
> could be written to use it as a function generator. People could
> write applications to use it to control all sorts of things --
> lighting, robotics, special effects, home theatre systems, internal
> combustion engines, whatever.
>
>
>
> On 3/3/06, coyoteous put forth:
> >MIDI has been obsolete for more than a decade, but is so implanted
> >that it will probably be here long after we are gone. Remember MIDI2
> >or ZIPI? MLAN is/was also supposed to be a MIDI killer. What we need
> >is a fast standardized duplex protocol for event information and
> >high resolution continuous control. Home brew "ghost electronics" +
> >MIDI are about as close as it gets or may ever get. I'd still like
> >to see a USB 2.0 or (IEEE1394/Firewire) to (and
> >from) CV module. But why limit to sub-sonics? Some cheap audio
> >interfaces pass DC on one end and/or the other, but as Paul S. has
> >pointed out in the past, the resolution in the sub-sonic range is
> >probably inadequate for precise 1V/oct pitch control. Planetarium
> >laser show controllers have used modified ADATs and sound cards to
> >accomplish a flavor of this for a long time. I would think there
> >would be some off-the-shelf industrial controller technology that
> >would do the job, but in my limited searching I haven't come up with
> >anything.
>